Terminal apparatus, base station apparatus, communication method, and integrated circuit

ABSTRACT

A terminal apparatus receives a first measurement configuration from a first base station apparatus via a first SRB and receives a second measurement configuration from a second base station apparatus via a second SRB, and transmits via the first SRB a first measurement result for the first measurement configuration configured from the first base station apparatus via the first SRB and transmits via the second SRB a second measurement result for the second measurement configuration configured from the second base station apparatus via the second SRB.

TECHNICAL FIELD

The present invention relates to a terminal apparatus, a base stationapparatus, a communication method, and an integrated circuit.

This application claims priority based on JP 2017-055588 filed on Mar.22, 2017, the contents of which are incorporated herein by reference.

BACKGROUND ART

A radio access method and a radio network for cellular mobilecommunications (hereinafter, referred to as “Long Term Evolution (LTE:Registered Trademark)”, or “Evolved Universal Terrestrial Radio Access(EUTRA)”) have been studied in the 3rd Generation Partnership Project(3GPP).

Furthermore, as a radio access method and a radio access networktechnology for a fifth-generation cellular system, the 3GPP isconducting a technical study of LTE-Advanced Pro, which is an enhancedtechnology of LTE, and New Radio Technology (NR), which is a new radioaccess technology, and formulating standards for the technologies (NPL1).

CITATION LIST Non Patent Literature

NPL 1: RP-161214, NTT DOCOMO, “Revision of SI: Study on New Radio AccessTechnology”, June 2016

NPL 2: 3GPP R2-1700574http://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_AHs/2017_01_NR/Docs/R2-1700574.zip

NPL 3: 3GPP R2-1701967http://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_97/Docs/R2-1701967.zip

SUMMARY OF INVENTION Technical Problem

A mechanism has been studied where cells of Radio Access Technology(RAT) for both LTE and NR are grouped into a cell group for each RAT tobe assigned to a terminal apparatus, and the terminal apparatus and oneor more base station apparatuses communicate with each other (E-UTRA-NRDual Connectivity: EN-DC) (NPL 2).

In EN-DC, a mechanism has been studied where the base station apparatusand the terminal apparatus directly configure and report some radioresource control (RRC) measurements for each cell group, and selectappropriate cells to be used for communication (NPL 3).

However, in Dual Connectivity (DC) using a conventional LTE cell, themeasurement configuration and report are performed only in one cellgroup, so there has been a problem in that in a case that this isapplied to multiple cell groups, communication between the base stationapparatus and the terminal apparatus cannot be efficiently performed.

An aspect of the present invention has been made in view of thecircumstances described above, and has an object to provide a terminalapparatus capable of efficiently communicating with a base stationapparatus, a base station apparatus communicating with the terminalapparatus, a communication method used for the terminal apparatus, acommunication method used for the base station apparatus, an integratedcircuit mounted on the terminal apparatus, and an integrated circuitmounted on the base station apparatus.

Solution to Problem

(1) In order to accomplish the object described above, an aspect of thepresent invention is contrived to provide the following measures.Specifically, an aspect of the present invention is a terminal apparatusfor receiving a measurement configuration from one or more base stationapparatuses, the measurement configuration including a measurementobject, a reporting configuration, and a measurement identifier, themeasurement object including at least an identifier for individuallyidentifying the measurement object (measurement object identifier) andinformation of a frequency to be measured, the reporting configurationincluding at least an identifier for individually identifying thereporting configuration (reporting configuration identifier) andinformation of a condition to be reported, and the measurementidentifier being an identifier for individually identifying informationfor indicating a combination of the measurement object identifier andthe reporting configuration identifier, the terminal apparatus includinga receiver configured to receive a first measurement configuration froma first base station apparatus via a first signaling radio bearer (firstSRB), and receive a second measurement configuration from a second basestation apparatus via a second signaling radio bearer (second SRB), anda transmitter configured to transmit via the first SRB a firstmeasurement result for the first measurement configuration configuredfrom the first base station apparatus via the first SRB, and transmitvia the second SRB a second measurement result for the secondmeasurement configuration configured from the second base stationapparatus via the second SRB.

(2) An aspect of the present invention is a communication method appliedto a terminal apparatus for receiving a measurement configuration fromone or more base station apparatuses, the measurement configurationincluding a measurement object, a reporting configuration, and ameasurement identifier, the measurement object including at least anidentifier for individually identifying the measurement object(measurement object identifier) and information of a frequency to bemeasured, the reporting configuration including at least an identifierfor individually identifying the reporting configuration (reportingconfiguration identifier) and information of a condition to be reported,and the measurement identifier being an identifier for individuallyidentifying information for indicating a combination of the measurementobject identifier and the reporting configuration identifier, thecommunication method including the steps of receiving a firstmeasurement configuration from a first base station apparatus via afirst signaling radio bearer (first SRB), and receiving a secondmeasurement configuration from a second base station apparatus via asecond signaling radio bearer (second SRB), and transmitting via thefirst SRB a first measurement result for the first measurementconfiguration configured from the first base station apparatus via thefirst SRB, and transmitting via the second SRB a second measurementresult for the second measurement configuration configured from thesecond base station apparatus via the second SRB.

(3) An aspect of the present invention is an integrated circuit mountedon a terminal apparatus for receiving a measurement configuration fromone or more base station apparatuses, the measurement configurationincluding a measurement object, a reporting configuration, and ameasurement identifier, the measurement object including at least anidentifier for individually identifying the measurement object(measurement object identifier) and information of a frequency to bemeasured, the reporting configuration including at least an identifierfor individually identifying the reporting configuration (reportingconfiguration identifier) and information of a condition to be reported,and the measurement identifier being an identifier for individuallyidentifying information for indicating a combination of the measurementobject identifier and the reporting configuration identifier, theintegrated circuit causing the terminal apparatus to exert receiving afirst measurement configuration from a first base station apparatus viaa first signaling radio bearer (first SRB) and receiving a secondmeasurement configuration from a second base station apparatus via asecond signaling radio bearer (second SRB), and transmitting via thefirst SRB a first measurement result for the first measurementconfiguration configured from the first base station apparatus via thefirst SRB and transmitting via the second SRB a second measurementresult for the second measurement configuration configured from thesecond base station apparatus via the second SRB.

Advantageous Effects of Invention

According to an aspect of the present invention, the terminal apparatusand the base station apparatus can communicate efficiently.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a conceptual diagram of a radio communication system accordingto the present embodiment.

FIG. 2 is a block diagram illustrating an example of a schematicconfiguration of a terminal apparatus according to an embodiment of thepresent invention.

FIG. 3 is a block diagram illustrating an example of a schematicconfiguration of a base station apparatus according to the embodiment ofthe present invention.

FIG. 4 is a diagram illustrating an example of a schematic configurationof a downlink slot according to the embodiment of the present invention.

FIG. 5 is a diagram illustrating a relationship between a subframe, aslot, and a mini-slot in a time domain according to the embodiment ofthe present invention.

FIG. 6 is a diagram illustrating an example of a slot or a subframeaccording to the embodiment of the present invention.

FIG. 7 is a diagram illustrating an example of an operation related toPSCell (SN) addition according to the embodiment of the presentinvention.

FIG. 8 is a diagram illustrating an example of an operation of an SNrelated to SCell addition according to the embodiment of the presentinvention.

FIG. 9 is a diagram illustrating an example of an operation of the SNrelated to SCell addition according to the embodiment of the presentinvention.

FIG. 10 is a diagram illustrating an example of an RRC connectionreconfiguration message according to the embodiment of the presentinvention.

FIG. 11 is a diagram illustrating an example of elements included in theRRC connection reconfiguration message according to the embodiment ofthe present invention.

FIG. 12 is a diagram illustrating an example of elements included in theRRC connection reconfiguration message according to an embodiment of thepresent invention.

FIG. 13 is a diagram illustrating an example of a measurementconfiguration procedure according to the embodiment of the presentinvention.

FIG. 14 is a diagram illustrating an example of a measurementconfiguration according to the embodiment of the present invention.

FIG. 15 is a diagram illustrating another example of a measurementconfiguration procedure according to the embodiment of the presentinvention.

FIG. 16 is a diagram illustrating another example of a measurementconfiguration according to the embodiment of the present invention.

FIG. 17 is a diagram illustrating an example of a measurement resultaccording to the embodiment of the present invention.

FIG. 18 is a diagram illustrating an example of a measurement result ofa serving cell according to the embodiment of the present invention.

FIG. 19 is a diagram illustrating an example of a measurement result ofa neighbor cell according to the embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described below.

A radio communication system and a radio network according to thepresent embodiment will be described.

LTE (and LTE-A Pro) and NR may be defined as different RATs. NR may bedefined as a technology included in LTE. LTE may be defined as atechnology included in NR. LTE connectable with NR by Dual connectivitymay be distinguished from conventional LTE. The present embodiment maybe applied to NR, LTE and other RATs. Terms associated with LTE and NRare used in the following description. However, the present inventionmay be applied to other technologies using other terms.

FIG. 1 is a conceptual diagram of a radio communication system accordingto the present embodiment. In FIG. 1, the radio communication systemincludes a terminal apparatus 2 and a base station apparatus 3. The basestation apparatus 3 may include one or more transmission receptionpoints (TRPs) 4. The base station apparatus 3 may have a communicablerange (communication area), controlled by the base station apparatus 3,that includes one or more cells to serve the terminal apparatus 2. Thebase station apparatus 3 may include a core network apparatus. The basestation apparatus 3 may have a communicable range (communication area),controlled by one or more transmission reception points 4, that includesone or more cells to serve the terminal apparatus 2. One cell may bedivided into multiple Beamed areas (also referred to as Beamed cells) toserve the terminal apparatus 2 in each of the beamed areas. Here, thebeamed area may be identified based on a beam index used forbeamforming, a quasi-collocation index or a precoding index.

The communication area covered by the base station apparatus 3 may bedifferent in a size and a shape for each frequency. The covered area maybe different for each frequency. A radio network, in which cells havingdifferent types of base station apparatuses 3 and different cell radiicoexist at the same frequency or different frequencies to form a singlecommunication system, is referred to as a heterogeneous network.

A radio communication link from the base station apparatus 3 to theterminal apparatus 2 is referred to as a downlink. A radio communicationlink from the terminal apparatus 2 to the base station apparatus 3 isreferred to as an uplink. A direct radio communication link from theterminal apparatus 2 to another terminal apparatus 2 is referred to as asidelink.

In FIG. 1, in a radio communication between the terminal apparatus 2 andthe base station apparatus 3, and/or a radio communication between theterminal apparatus 2 and another terminal apparatus 2, OrthogonalFrequency Division Multiplexing (OFDM) including a Cyclic Prefix (CP),Single-Carrier Frequency Division Multiplexing (SC-FDM), DiscreteFourier Transform Spread OFDM (DFT-S-OFDM), or Multi-Carrier CodeDivision Multiplexing (MC-CDM) may be used.

In FIG. 1, in the radio communication between the terminal apparatus 2and the base station apparatus 3, and/or the radio communication betweenthe terminal apparatus 2 and another terminal apparatus 2,Universal-Filtered Multi-Carrier (UFMC), Filtered OFDM (F-OFDM), OFDM inwhich a window is multiplied (Windowed OFDM), or Filter-BankMulti-Carrier (FBMC) may be used.

Note that the present embodiment will be described by using OFDM symbolwith the assumption that a transmission scheme is OFDM, and use of anyother transmission scheme is also included in an aspect of the presentinvention. For example, the OFDM symbol in the present embodiment may beSC-FDM symbols (also referred to as Single-Carrier Frequency DivisionMultiple Access (SC-FDMA) symbols).

In FIG. 1, in the radio communication between the terminal apparatus 2and the base station apparatus 3, and/or the radio communication betweenthe terminal apparatus 2 and another terminal apparatus 2, theabove-described transmission scheme that uses no CP or uses zero paddinginstead of the CP may be employed. The CP and the zero padding may beadded both forward and backward.

The terminal apparatus 2 operates while considering the inside of a cellas a communication area. The terminal apparatus 2 may move to anotherappropriate cell through a cell re-selection procedure in a case thatthe terminal apparatus 2 is not wirelessly connected (also referred toas an idle state or an RRC_IDLE state). The terminal apparatus 2 maymove to another cell through a handover procedure in a case that theterminal apparatus 2 is wirelessly connected (also referred to as aconnected state, or an RRC_CONNECTED state). The appropriate cellgenerally refers to a cell that may be found not to prohibit access fromthe terminal apparatus 2, based on information indicated by the basestation apparatus 3 and that has a downlink reception quality satisfyinga predefined condition. The terminal apparatus 2 may move to anotherappropriate cell through a cell re-selection procedure in a case thatthe terminal apparatus 2 is in an non-active state (also referred to asan inactive state). The terminal apparatus 2 may move to another cellthrough a handover procedure in the inactive state.

In a case that the terminal apparatus 2 can communicate with a certainbase station apparatus 3, any of the cells of the base station apparatus3 which is configured to be used for the communication with the terminalapparatus 2 may be referred to as a Serving cell while the other cellswhich are not used for the communication may be referred to asNeighboring cells. Some or all pieces of the system information requiredin the serving cell may be broadcast or notified to the terminalapparatus 2 through another cell.

In the present embodiment, one or more serving cells are configured forthe terminal apparatus 2. In a case that multiple serving cells areconfigured for the terminal apparatus 2, multiple configured servingcells may include one primary cell and one or more secondary cells. Theprimary cell may be a serving cell in which an initial connectionestablishment procedure has been performed, a serving cell in which aconnection re-establishment procedure has been initiated, or a cellindicated as the primary cell by a handover procedure. One or moresecondary cells may be configured at a point of time at which a RadioResource Control (RRC) connection is established or after the RRCconnection is established. A cell group (also referred to as a mastercell group (MCG)) including one or more serving cells including aprimary cell (PCell), and one or more cell groups (also referred to assecondary cell groups (SCGs)) including one or more serving cells notincluding a primary cell and including a primary secondary cell (PSCell)in which at least a random access procedure can be performed and whichdoes not become a deactivated state may be configured for the terminalapparatus 2. The master cell group includes one primary cell and zero ormore secondary cells. The secondary cell group includes one primarysecondary cell and zero or more secondary cells. Any of the MCG and theSCG may be a cell group including LTE cells.

Time Division Duplex (TDD) and/or Frequency Division Duplex (FDD) may beapplied to the radio communication system according to the presentembodiment. A Time Division Duplex (TDD) scheme or a Frequency DivisionDuplex (FDD) scheme may be applied to all of multiple cells. Cells towhich the TDD scheme is applied and cells to which the FDD scheme isapplied may be aggregated.

A carrier corresponding to a serving cell in the downlink is referred toas a downlink component carrier (or a downlink carrier). A carriercorresponding to a serving cell in the uplink is referred to as anuplink component carrier (or an uplink carrier). A carrier correspondingto a serving cell in the sidelink is referred to as a sidelink componentcarrier (or a sidelink carrier). The downlink component carrier, theuplink component carrier, and/or the sidelink component carrier arecollectively referred to as a component carrier (or a carrier).

Physical channels and physical signals according to the presentembodiment will be described. However, the downlink physical channelsand/or the downlink physical signals may be collectively referred to asdownlink signals. The uplink physical channels and/or the uplinkphysical signals may be collectively referred to as uplink signals. Thedownlink physical channels and/or the uplink physical channels may becollectively referred to as physical channels. The downlink physicalsignals and/or the uplink physical signals may be collectively referredto as physical signals.

In FIG. 1, the following downlink physical channels are used fordownlink radio communication between the terminal apparatus 2 and thebase station apparatus 3. The downlink physical channels are used fortransmitting information output from a higher layer.

-   -   New Radio Physical Broadcast CHannel (NR-PBCH)    -   New Radio Physical Downlink Control CHannel (NR-PDCCH)    -   New Radio Physical Downlink Shared CHannel (NR-PDSCH)

The NR-PBCH is used by the base station apparatus 3 to broadcastimportant information block (Master Information Block (MIB) andEssential Information Block (EIB)) including important systeminformation (Essential Information) needed by the terminal apparatus 2.Here, one or more important information blocks may be transmitted asimportant information messages. For example, the important informationblock may include information indicating a part or all of a frame number(System Frame Number (SFN) (e.g., information about a location in asuperframe including multiple frames). For example, the radio frame (10ms) includes 10 subframes of 1 ms and the radio frame is identified bythe frame number. The frame number returns to 0 at 1024 (Wrap around).In a case that important information blocks different for each areawithin the cell are transmitted, information capable of identifying anarea (for example, identifier information of a base station transmissionbeam constituting the area) may be included. Here, the identifierinformation of the base station transmission beam may be indicated byusing an index of the base station transmission beam (precoding). In acase that important information blocks (important information messages)different for each area within the cell are transmitted, informationcapable of identifying a time location within the frame (for example, asubframe number in which the important information block (importantinformation message) is included) may be included. That is, informationfor determining each of the subframe numbers in which the respectiveimportant information blocks (important information messages) using theindexes of the different base station transmission beams are transmittedmay be included. For example, information necessary for connection tothe cell and for mobility may be included in the important information.The important information message may be a part of a system informationmessage. Some or all of the important information messages may bereferred to as minimum system information (Minimum SI). In a case thatnone of the valid minimum system information in a given cell isacquired, the terminal apparatus 2 may consider the cell as a cell(Barred Cell) to which access is prohibited. Only a part of the minimumsystem information may be broadcast on the PBCH and the remainingminimum system information may be transmitted on the NR-PSCH, which willbe described later.

The NR-PDCCH is used to transmit Downlink Control Information (DCI) in adownlink radio communication (radio communication from the base stationapparatus 3 to the terminal apparatus 2). Here, one or more pieces ofDCI (which may be referred to as DCI formats) are defined fortransmission of the downlink control information. That is, a field forthe downlink control information is defined as the DCI, and is mapped toinformation bits.

For example, the DCI may be defined to include information indicating atiming for transmitting a HARQ-ACK for a scheduled NR-PDSCH (forexample, the number of symbols from the last symbol included in theNR-PDSCH to the HARQ-ACK transmission).

For example, the DCI may be defined to be used for scheduling onedownlink radio communication NR-PDSCH in one cell (transmission of onedownlink transport block).

For example, the DCI may be defined to be used for scheduling one uplinkradio communication NR-PUSCH in one cell (transmission of one uplinktransport block).

Here, the DCI includes information on scheduling of the NR-PDSCH orNR-PUSCH. Here, the DCI for the downlink is also referred to as downlinkgrant or downlink assignment. Here, the DCI for the uplink is alsoreferred to as uplink grant or Uplink assignment.

The NR-PDSCH is used to transmit downlink data (Downlink Shared CHannel(DL-SCH)) from medium access (Medium Access Control (MAC)). The NR-PDSCHis also used to transmit System Information (SI), Random Access Response(RAR), and the like.

Here, the base station apparatus 3 and the terminal apparatus 2 exchange(transmit and/or receive) signals with each other in a higher layer. Forexample, the base station apparatus 3 and the terminal apparatus 2 maytransmit and/or receive, in a Radio Resource Control (RRC) layer, RRCsignaling (also referred to as Radio Resource Control message (RRCmessage), radio Resource Control information (RRC information)). Thebase station apparatus 3 and the terminal apparatus 2 may transmitand/or receive, in a Medium Access Control (MAC) layer, a MAC controlelement. Here, the RRC signaling and/or the MAC control element is alsoreferred to as higher layer signaling. Here, the higher layer means ahigher layer viewed from the physical layer, and thus may include one ormore of a MAC layer, an RRC layer, an RLC layer, a PDCP layer, a NASlayer, and the like. For example, in processing of the MAC layer, thehigher layer may include one or more of an RRC layer, an RLC layer, aPDCP layer, a NAS layer, and the like.

The NR-PDSCH may be used to transmit the RRC signaling and the MACcontrol element. Here, the RRC signaling transmitted from the basestation apparatus 3 may be signaling common to multiple terminalapparatuses 2 in a cell. The RRC signaling transmitted from the basestation apparatus 3 may be signaling dedicated to a certain terminalapparatus 2 (also referred to as dedicated signaling). In other words,information specific to the terminal apparatus (UE specific information)may be transmitted through signaling dedicated to the certain terminalapparatus 2.

The NR-PRACH may be used to transmit a random access preamble. TheNR-PRACH may be used to indicate an initial connection establishmentprocedure, a handover procedure, a connection re-establishmentprocedure, uplink transmission synchronization (timing adjustment), andan NR-PUSCH (UL-SCH) resource request.

In FIG. 1, the following downlink physical signals are used for thedownlink radio communication. Here, the downlink physical signals arenot used to transmit the information output from the higher layers butis used by the physical layer.

-   -   Synchronization signal (SS)    -   Reference Signal (RS)

The synchronization signal is used for the terminal apparatus 2 to takesynchronization in the frequency domain and the time domain in thedownlink. The synchronization signal may include a PrimarySynchronization Signal (PSS) and a secondary synchronization signal(Second Synchronization Signal (SSS)). The synchronization signal may beused for the terminal apparatus 2 to identify a cell identifier (alsoreferred to as a Cell Identifier (cell ID), or Physical Cell Identifier(PCI)). The synchronization signal may also be used toselect/identify/determine a base station transmission beam to be used bythe base station apparatus 3 for downlink beamforming, and/or a terminalreception beam to be used by the terminal apparatus 2. In other words,the synchronization signal may be used to allow the terminal apparatus 2to select/identify/determine the index of the base station transmissionbeam applied to the downlink signal by the base station apparatus 3. Thesynchronization signal, the primary synchronization signal, and thesecondary synchronization signal used in NR may be referred to as NR-SS,NR-PSS, and NR-SSS, respectively. The synchronization signal may also beused to measure a quality of the cell. For example, a received power(SSRP) and a reception quality (SSRQ) of the synchronization signal maybe used for measurement. The synchronization signal may be used toperform channel compensation on some of the downlink physical channels.

The downlink reference signal (hereinafter, also referred to simply as areference signal in the present embodiment) may be classified intomultiple reference signals, based on applications and the like. Forexample, one or more of the following reference signals may be used forthe reference signal.

-   -   Demodulation Reference Signal (DMRS)    -   Channel State Information Reference Signal (CSI-RS)    -   Phase Tracking Reference Signal (PTRS)    -   Mobility Reference Signal (MRS)

The DMRS may be used for channel compensation in demodulating a receivedmodulated signal. The DMRS may collectively refer to, or may beindividually defined for, DMRS for NR-PDSCH demodulation, DMRS forNR-PDCCH demodulation, and/or DMRS for NR-PBCH demodulation.

The CSI-RS may be used for channel state measurement. The PTRS may beused to track a phase due to movement of the terminal or the like. TheMRS may be used to measure the reception quality from multiple basestation apparatuses for handover.

A reference signal for compensating a phase noise may be defined for thereference signal.

However, functions of at least some of multiple reference signalsdescribed above may be included in other reference signals.

At least one of multiple reference signals described above or otherreference signals may be defined as a Cell-specific reference signal(CRS) that is configured individually for the cell, a Beam-specificreference signal (BRS) for each transmit beam used by the base stationapparatus 3 or the transmission reception point 4, and/or a UE-specificreference signal (URS) that is configured individually for the terminalapparatus 2.

At least one of the reference signals may be used for the radioparameters, numerologies for a subcarrier spacing, or Finesynchronization sufficient to achieve FFT window synchronization.

At least one of the reference signals may be used for Radio ResourceMeasurement (RRM). At least one of the reference signals may be used forbeam management. The radio resource measurements are also referred tobelow simply as measurements.

At least one of the reference signals may include a synchronizationsignal.

In FIG. 1, the following uplink physical channels are used for uplinkradio communication between the terminal apparatus 2 and the basestation apparatus 3 (or, radio communication from the terminal apparatus2 to the base station apparatus 3). The uplink physical channels areused to transmit information output from a higher layer.

-   -   New Radio Physical Uplink Control CHannel (NR-PUCCH)    -   New Radio Physical Uplink Shared CHannel (NR-PUSCH)    -   New Radio Physical Random Access CHannel (NR-PRACH)

The NR-PUCCH is used to transmit Uplink Control Information (UCI). Here,the uplink control information may include Channel State Information(CSI) used to indicate a downlink channel state. The uplink controlinformation may include a Scheduling Request (SR) used to request anUL-SCH resource. The uplink control information may include a HybridAutomatic Repeat request ACKnowledgment (HARQ-ACK). The HARQ-ACK mayindicate a HARQ-ACK for downlink data (Transport block, Medium AccessControl Protocol Data Unit (MAC PDU), Downlink-Shared Channel (DL-SCH)).

The NR-PDSCH is used to transmit uplink data (Uplink Shared CHannel(UL-SCH)) from medium access (Medium Access Control (MAC)). The NR-PUSCHmay be used to transmit a HARQ-ACK and/or CSI along with the uplinkdata. The NR-PUSCH may be used to transmit CSI only, or a HARQ-ACK andCSI only. That is, the NR-PUSCH may be used to transmit the UCI only.

The NR-PUSCH may be used to transmit the RRC signaling and the MACcontrol element. The NR-PUSCH may be used to transmit UE Capability inthe uplink.

Note that for the NR-PDCCH and the NR-PUCCH, the same referenceappellation (for example, NR-PCCH) and the same channel definition maybe used. For the NR-PDSCH and the NR-PUSCH, the same referenceappellation (for example, NR-PSCH) and the same channel definition maybe used.

The BCH, the UL-SCH, and the DL-SCH are transport channels. A channelused in a Medium Access Control (MAC) layer is referred to as atransport channel. A unit of the transport channel used in the MAC layeris also referred to as a transport block (TB) or a MAC Protocol DataUnit (PDU). The transport block is a unit of data that the MAC layerdelivers to the physical layer. In the physical layer, the transportblock is mapped to a codeword, and coding processing is performed foreach codeword.

A radio protocol structure according to the present embodiment will bedescribed.

In the present embodiment, a protocol stack handling user data of theterminal apparatus 2 and the base station apparatus 3 is referred to asUser-plane (U-plane (UP)) protocol stack, and a protocol stack handlingcontrol data is referred to as Control-plane (C-plane (CP)) protocolstack.

The Physical layer (PHY layer) uses the Physical Channels to provide atransmission service to a higher layer. The PHY layer is connected witha Medium Access Control layer (MAC layer), which is a higher layer, viathe transport channels. The data is exchanged via the transport channelsbetween layers, that is, the MAC layer and the PHY layer. The data istransmitted and/or received via the physical channels between the PHYlayers of the terminal apparatus 2 and the base station apparatus 3.

The MAC layer maps various logical channels to the various transportchannels. The MAC layer is connected with a Radio Link Control layer(RLC layer), which is a higher layer, via the logical channels. Thelogical channels are roughly classified depending on a type oftransmitted information, specifically, classified into the controlchannels transmitting the control information and the traffic channelstransmitting the user information. The MAC layer has a function tocontrol the PHY layer in order to perform Discontinuous Reception andTransmission (DRX and DTX), a function to perform a random accessprocedure, a function to report transmit power information, a functionto perform HARQ control, and the like.

The RLC layer performs Segmentation of the data received from the higherlayer to adjust its data size so that a lower layer can appropriatelytransmit the data. The RLC layer also has a function to ensure Qualityof Service (QoS) required for each data. In other words, the RLC layerhas a function of data re-transmission control or the like.

A Packet Data Convergence Protocol layer (PDCP layer) may have a headercompression function to compress unnecessary control information inorder to efficiently transmit an IP packet, which is the user data, in aradio segment. The PDCP layer may also have a data encryption function.

Furthermore, a Radio Resource Control layer (RRC layer) is present inthe control-plane protocol stack. The RRC layer performs configurationand reconfiguration of Radio Bearers (RBs) to control the logicalchannels, the transport channels, and the physical channels. The RBs maybe classified into a Signaling Radio Bearer (SRB) and a Data RadioBearer (DRB), and the SRB may be used as a path for transmitting an RRCmessage, which is the control information. The DRB may be used as a pathfor transmitting the user data. The RBs may be configured between theRRC layers of the base station apparatus 3 and the terminal apparatus 2.

The SRB is defined as a radio bearer used to transmit the RRC messageand the NAS message. Further, the SRB to be defined may include an SRB(SRB0) for RRC messages using a CCCH logic channel, an SRB (SRB1) forRRC messages using a DCCH logic channel as well as for NAS messagestransmitted prior to the establishment of SRB2, and an SRB (SRB2) forRRC messages including Logged measurement information and the like aswell as for NAS messages using a DCCH logical channels. Other SRBs mayalso be defined.

An MCG SRB is transmitted using the SRB of the MCG. An MCG Split SRB istransmitted using the SRB of the MCG or SCG, but is described herein asthe MCG SRB because the PDCP is allocated on the MCG side. In otherwords, the “MCG SRB” may be replaced with the “MCG SRB and/or MCG SplitSRB”. The SCG SRB is transmitted using the SRB of the SCG. An SCG SplitSRB is transmitted using the SRB of the MCG or SCG, but is describedherein as the SCG SRB because the PDCP is allocated on the SCG side. Inother words, the “SCG SRB” may be replaced with the “SCG SRB and/or SCGSplit SRB”.

The MCG SRB may be provided with SRB0, SRB1, and SRB2. The SCG SRB maybe provided with no SRB0 and/or SRB1.

The NAS and RRC messages may be sent via the MCG SRB, and the RRCmessages may be sent via the SCG SRB. The NAS messages may not be sentvia the SCG SRB.

Note that the PHY layer corresponds to a physical layer as the firstlayer in the layered structure of the generally known Open SystemsInterconnection (OSI) model. The MAC layer, the RLC layer, and the PDCPlayer correspond to a data link layer as the second layer in the OSImodel. The RRC layer corresponds to a network layer as the third layerin the OSI model.

The functional classification of the MAC layer, the RLC layer, and thePDCP layer described above is an example, and some or all of thefunctions may not be implemented. Some or all of the functions of eachlayer may be included in another layer. For example, when viewed fromthe physical layer, the control element in the MAC layer and the RRCsignaling are higher layer signaling. For example, when viewed from theMAC layer, the RRC signaling is higher layer signaling. When viewed fromthe RRC layer, the MAC layer and the physical layer are lower layers.When viewed from the RRC layer, for example, the NAS layer is alsoreferred to as an Upper Layer.

A signaling protocol used between the network and the terminal apparatus2 is classified into an Access Stratum (AS) protocol and a Non-AccessStratum (NAS) protocol. For example, a protocol in the RRC layer or in alower layer is the Access Stratum protocol used between the terminalapparatus 2 and the base station apparatus 3. Further, a protocol suchas Connection Management (CM) and Mobility Management (MM) of theterminal apparatus 2 is the Non-Access Stratum protocol, and is usedbetween the terminal apparatus 2 and a core network (CN). For example,between the terminal apparatus 2 and a Mobility Management Entity (MME),communication using the Non-Access Stratum protocol is transparentlyperformed via the base station apparatus 3.

Hereinafter, the subframe will be described. The subframe in theembodiment may also be referred to as a resource unit, a radio frame, atime period, or a time interval. One or more subframes may constituteone radio frame.

FIG. 4 is a diagram illustrating an example of a schematic configurationof a downlink slot according to the embodiment of the present invention.Each of the radio frames is 10 ms in length. Each of the radio framesincludes 10 subframes and X slots. That is, a length of one subframe is1 ms. For each of the slots, a time length is defined depending on asubcarrier spacing. For example, in a case that a subcarrier spacing ofOFDM symbols is 15 kHz with a Normal Cyclic Prefix (NCP), X=7 or X=14,where the time length of the slot is 0.5 ms or 1 ms, respectively. In acase the subcarrier spacing is 60 kHz, X=7 or X=14, where the timelength of the slot is 0.125 ms or 0.25 ms, respectively. FIG. 2illustrates a case of X=7 as an example. Note that in a case of X=14,the same expansion can be achieved. The uplink slot may be definedsimilarly, and the downlink slot and the uplink slot may be definedseparately.

The signal or the physical channel transmitted in each of the slots isexpressed by a resource grid. The resource grid is defined by multiplesubcarriers and multiple OFDM symbols. The number of subcarriersconstituting one slot depends on cell downlink and uplink bandwidths.Each element within the resource grid is referred to as a resourceelement. The resource element may be identified by a subcarrier numberand an OFDM symbol number.

A resource block is used to express mapping of resource elements for acertain physical downlink channel (such as the PDSCH) or a certainphysical uplink channel (such as the PUSCH). For the resource block, avirtual resource block and a physical resource block are defined. Acertain physical uplink channel is first mapped to a virtual resourceblock. Thereafter, the virtual resource block is mapped to the physicalresource block. In a case that the number X of OFDM symbols in a slot is7 (X=7) with the NCP, one physical resource block is defined by sevenOFDM symbols consecutive in the time domain and by 12 subcarriersconsecutive in the frequency domain. Specifically, one physical resourceblock includes (7×12) resource elements. In a case of an Extended CP(ECP), for example, one physical resource block is defined by six OFDMsymbols consecutive in the time domain and by 12 subcarriers consecutivein the frequency domain. Specifically, one physical resource blockincludes (6×12) resource elements. At this time, one physical resourceblock corresponds to one slot in the time domain and corresponds to 180kHz in the frequency domain in a case of the 15 kHz subcarrier spacing(or, 720 kHz in a case of the 60 kHz subcarrier spacing). The physicalresource blocks are numbered from zero in the frequency domain.

Next, the subframe, the slot, and the mini-slot will be described. FIG.5 is a diagram illustrating a relationship between the subframe, theslot, and the mini-slot in the time domain. As illustrated in thedrawing, three kinds of time units are defined. The subframe is 1 msregardless of the subcarrier spacing, the number of OFDM symbolsincluded in the slot is 7 or 14, and the slot length depends on thesubcarrier spacing. Here, in the case of the subcarrier spacing of 15kHz, 14 OFDM symbols are included in the one subframe. Thus, in a casethat the subcarrier spacing is Δf (kHz), the slot length may be definedas 0.5/(Δf/15) ms in the case that the number of OFDM symbolsconstituting one slot is 7. Here, Δf may be defined by the subcarrierspacing (kHz). In the case that the number of OFDM symbols constitutingone slot is 7, the slot length may be defined as 1/(Δf/15) ms. Here, Δfmay be defined by the subcarrier spacing (kHz). Furthermore, in a casethat the number of OFDM symbols included in the slot is X, the slotlength may be defined as X/14/(Δf/15) ms.

The mini-slot (which may be referred to as a sub-slot) is a time unitincluding OFDM symbols that are less than the number of OFDM symbolsincluded in the slot. The drawing illustrates a case that the mini-slotincludes two OFDM symbols as an example. The OFDM symbol in themini-slot may match an OFDM symbol timing that constitutes the slot.Note that a minimum unit of scheduling may be a slot or a mini-slot.

FIG. 6 illustrates an example of the slot or the subframe (subframetype). Here, a case that the slot length is 0.5 ms with the subcarrierspacing 15 kHz is illustrated as an example. In the drawing, “D”represents the downlink, and “U” represents the uplink. As illustratedin the drawing, a certain time period (for example, a minimum timeperiod to be allocated to one UE in the system) may include one or moreof the followings:

-   -   a downlink part (duration),    -   a gap, and    -   a uplink part (duration).

(a) in FIG. 6 is an example in which a certain time period (which may bereferred to as, for example, a minimum unit of time resource that can beallocated to one UE, a time unit, or the like, or multiple minimum unitsof time resource may be bundled and referred to as a time unit) isentirely used for downlink transmission. (b) in FIG. 6 illustrates anexample in which the first time resource is used for an uplinkscheduling via a PCCH, for example, and then, through a gap for aprocessing delay of the PCCH, a time for switching from a downlink to anuplink, and generation of a transmit signal, an uplink signal istransmitted. (c) in FIG. 6 illustrates an example in which the firsttime resource is used for a downlink PCCH and/or downlink PSCHtransmission, and then, through a gap for a processing delay, a time forswitching from a downlink to an uplink, and generation of a transmitsignal, a PSCH or PCCH is transmitted. Here, as an example, the uplinksignal may be used to transmit the HARQ-ACK and/or CSI, namely, the UCI.(d) in FIG. 6 illustrates an example in which the first time resource isused for a downlink PCCH and/or downlink PSCH transmission, and then,through a gap for a processing delay, a time for switching from adownlink to an uplink, and generation of a transmit signal, the uplinkPSCH and/or PCCH is transmitted. Here, as an example, the uplink signalmay be used to transmit the uplink data, namely, the UL-SCH. (e) in FIG.6 illustrates an example in which the entire time resource is used foruplink transmission (uplink PSCH or PCCH).

The above-described downlink part and uplink part may include multipleOFDM symbols as is the case with LTE.

The LTE measurement will be described.

The base station apparatus 3 uses an RRC connection reconfiguration(RRCConnectionReconfiguration) message of the RRC signaling (radioresource control signalling) to transmit a Measurement configurationmessage to the terminal apparatus 2. The terminal apparatus 2 configuressystem information included in the Measurement configuration message,and in accordance with the notified system information, performsmeasurement, event evaluation, and measurement report for a serving celland a neighbor cell (including a listed cell and/or a detected cell).The listed cell is a cell that is listed within a Measurement object (acell notified as a neighbor cell list by the base station apparatus 3 tothe terminal apparatus 2), and the detected cell is a cell that isdetected by the terminal apparatus 2 on a frequency indicated by theMeasurement object, but is not listed within the Measurement object (acell detected by the terminal apparatus 2 itself and not notified as aneighbor cell list).

The measurement includes three types, intra-frequency measurements,inter-frequency measurements, and inter-radio access technologymeasurements (inter-RAT measurements). The intra-frequency measurementsare a measurement at a downlink frequency in the serving cell. Theinter-frequency measurements are a measurement at a frequency differentfrom the downlink frequency in the serving cell. The inter-radio accesstechnology measurements (inter-RAT measurements) are a measurement usinga radio technology (e.g. UTRA, GERAN, CDMA2000, etc.) different from theradio technology in the serving cell (e.g. EUTRA). The inter-RATmeasurements may include NR measurements.

The Measurement configuration message includes a measurement identifier(measId), Measurement object(s), addition and/or modification and/ordeletion of Reporting configuration(s), a quantity configuration(quantityConfig), a measurement gap configuration (measGapConfig), aserving cell quality threshold (s-Measure), and the like.

Quantity Configuration (quantityConfig)

The quantity configuration (quantityConfig) specifies a layer-3filtering coefficient (L3 filtering coefficient) in a case that themeasurement object is EUTRA. The layer-3 filtering coefficient (L3filtering coefficient) specifies a ratio between the latest measurementresult and the past measurement result. The filtering result is used forthe event evaluation in the terminal apparatus 2.

Measurement Gap Configuration (measGapConfig)

The measurement gap configuration (measGapConfig) is utilized toconfigure a measurement gap pattern or control activation/deactivationof a measurement gap. In the measurement gap configuration(measGapConfig), the gap pattern, a start system frame number(startSFN), and a start subframe number (startSubframeNumber) arenotified as information for activating the measurement gap. The gappattern specifies which pattern to use as a measurement gap. The startsystem frame number (startSFN) specifies a System Frame Number (SFN) forstarting the measurement gap. The start subframe number(startSubframeNumber) specifies a subframe number for starting themeasurement gap.

Serving Cell Quality Threshold (s-Measure)

The serving cell quality threshold (s-Measure) represents a thresholdfor the quality of the serving cell, and is used to control whether theterminal apparatus 2 needs to perform measurement. The serving cellquality threshold (s-Measure) is configured as a value for referencesignal received power (RSRP).

Measurement Identifier (measId)

Here, the measurement identifier (measId) is utilized to link theMeasurement object and the Reporting configuration, and specifically, tolink a measurement object identifier (measObjectId) and a reportingconfiguration identifier (reportConfigId). The measurement identifier(measId) is associated with one measObjectId and one reportingconfiguration identifier (reportConfigId). The Measurement configurationmessage can make addition, modification, and deletion with respect tothe relationship between the measurement identifier (measId), theMeasurement object, and the Reporting configuration.

measObjectToRemoveList is a command to delete a specified measObjectIdand a Measurement object corresponding to the specified measurementobject identifier (measObjectId). At this time, all the measurementidentifier (measId) associated with the specified measurement objectidentifier (measObjectId) are deleted. This command can simultaneouslyspecify multiple measurement object identifiers (measObjectIds).

measObjectToAddModifyList is a command to modify a specified measurementobject identifier (measObjectId) to a specified Measurement object, orto add a specified measurement object identifier (measObjectId) and aspecified Measurement object. This command can simultaneously specifymultiple measurement object identifiers (measObjectIds).

reportConfigToRemoveList is a command to delete a specified reportingconfiguration identifier (reportConfigId) and a Reporting configurationcorresponding to the specified reporting configuration identifier(reportConfigId). At this time, all the measurement identifiers(measIds) associated with the specified reporting configurationidentifier (reportConfigId) are deleted. This command can simultaneouslyspecify multiple reporting configuration identifiers (reportConfigIds).

reportConfigToAddModifyList is a command to modify a specified reportingconfiguration identifier (reportConfigId) to a specified Reportingconfiguration, or to add a specified reporting configuration identifier(reportConfigId) and a specified Reporting configuration. This commandcan simultaneously specify multiple reporting configuration identifiers(reportConfigIds).

measIdToRemoveList is a command to delete the specified measurementidentifier (measId). At this time, the measurement object identifier(measObjectId) and the reporting configuration identifier(reportConfigId) associated with the specified measurement identifier(measId) are maintained without being deleted. This command cansimultaneously specify multiple measurement identifiers (measIds).

measIdToAddModifyList is a command to modify a specified measurementidentifier (measId) to be associated with a specified measurement objectidentifier (measObjectId) and a specified reporting configurationidentifier (reportConfigId), or to associate a specified measurementobject identifier (measObjectId) and a specified reporting configurationidentifier (reportConfigId) with a specified measurement identifier(measId) to add the specified measurement identifier (measId). Thiscommand can simultaneously specify multiple measurement identifiers(measIds).

Measurement Objects

The Measurement object is specified for each RAT and frequency. TheReporting configuration includes a specification for the EUTRA and aspecification for the RAT other than the EUTRA.

The Measurement object includes a measurement object EUTRA(measObjectEUTRA), a measurement object UTRA (measObjectUTRA), ameasurement object GERAN (measObjectGERAN), a measurement objectCDMA2000 (measObjectCDMA2000), a measurement object WLAN(measObjectWLAN), and the like which are associated with the measurementobject identifier (measObjectId). The Measurement object may include ameasurement object NR (measObjectNR) associated with the measurementobject identifier (measObjectId).

The measurement object identifier (measObjectId) is an identifier usedto identify configurations of Measurement objects. The configuration ofthe Measurement object is specified for each Radio Access Technology(RAT) and for each frequency as described above. The Measurement objectis otherwise specified for EUTRA, UTRA, GERAN, CDMA2000. The measurementobject for EUTRA (measObjectEUTRA), which is a Measurement object forEUTRA, specifies information to be applied to a neighbor cell of theEUTRA. Any of the measurement objects for EUTRA (measObjectEUTRA) thathas a different frequency is treated as a different Measurement object,and assigned with another measurement object identifier (measObjectId).

The measurement object for EUTRA (measObjectEUTRA) includes EUTRAcarrier frequency information (eutra-CarrierInfo), a measurementbandwidth (measurementBandwidth), offset frequency (offsetFreq),information on a neighbor cell list (neighbour cell list), andinformation on a black list.

Next, information included in the measurement object for EUTRA(measObjectEUTRA) will be described. The EUTRA carrier frequencyinformation (eutra-CarrierInfo) specifies a carrier frequency to bemeasured. The measurement bandwidth (measurementBandwidth) indicates ameasurement bandwidth common to all neighbor cells operating at thecarrier frequency to be measured. The offset frequency (offsetFreq)indicates a measurement offset value to be applied at the frequency tobe measured.

The information on a neighbor cell list (neighbour cell list) includesinformation regarding event evaluations and neighbor cells to be subjectto measurement report. The information on the neighbor cell list(neighbour cell list) includes a physical cell identifier (physical cellID), a cell-specific offset (cellIndividualOffset, indicating ameasurement offset value applied to the neighbor cell), and the like. Inthe case of the EUTRA, this information is used as information foradding, modifying, or deleting the neighbor cell list (neighbour celllist) which the terminal apparatus 2 has already acquired from thebroadcast information (broadcast system information).

The information on a black list includes information regarding eventevaluations and neighbor cells not to be subject to measurement report.The information on the black list includes a physical cell identifier(physical cell ID) and the like. In the case of the EUTRA, thisinformation is used as information for adding, modifying, or deletingthe black cell list (black listed cell list) which the terminalapparatus 2 has already acquired from the broadcast information.

Reporting Configurations

The Reporting configuration includes a report configuration EUTRA(reportConfigEUTRA) associated with a reporting configuration identifier(reportConfigId), and the like.

The reporting configuration identifier (reportConfigId) is an identifierused to identify a Reporting configuration related to the measurement.The Reporting configuration related to the measurement include aspecification for the EUTRA and a specification for the RAT other thanthe EUTRA (UTRA, GERAN, CDMA2000) as described above. The reportconfiguration EUTRA (reportConfigEUTRA), which is a Reportingconfiguration for the EUTRA, specifies triggering criteria of an eventused for measurement report in the EUTRA.

The report configuration EUTRA (reportConfigEUTRA) includes an eventidentifier (eventId), a trigger quantity (triggerQuantity), ahysteresis, a trigger time (timeToTrigger), a report quantity(reportQuantity), the number of maximum report cells (maxReportCells), areport interval (reportInterval), and a report amount (reportAmount).

Next, the report configuration EUTRA (reportConfigEUTRA) will bedescribed. The event identifier (eventId) is used to select criteriarelated to an event triggered reporting. Here, the event triggeredreporting refers to a method for reporting a measurement in a case thatthe event triggered criteria are satisfied. Besides this, there is anevent triggered periodic reporting in which the measurement is reportedby a prescribed number of times at a constant interval in a case thatthe event triggered criteria are satisfied.

At least eight types described later are specified as the eventtriggered criterion. Specifically, in a case that the event triggeredcriteria specified by the event identifier (eventId) are satisfied, theterminal apparatus 2 performs a measurement report on the base stationapparatus 3. The trigger quantity (triggerQuantity) is a quantityutilized to evaluate the event triggered criteria. Specifically, aReference Signal Received Power (RSRP) or a Reference Signal ReceivedQuality (RSRQ) are specified. That is, the terminal apparatus 2 measuresthe downlink reference signal by use of a quantity specified by thetrigger quantity (triggerQuantity) to determine whether or not the eventtrigged criteria specified by the event identifier (eventId) aresatisfied. The hysteresis is a parameter utilized in the event triggeredcriteria. The trigger time (timeToTrigger) indicates a period in whichthe event triggered criteria is to be met. The report quantity(reportQuantity) indicates a quantity reported in the measurementreport. Here, the quantity specified by the trigger quantity(triggerQuantity), or the reference signal received power (RSRP) and thereference signal received quality (RSRQ) are specified. Here, thereference signal received quality (RSRQ) is a ratio expressed by(N*RSRP)/(EUTRA Carrier RSSI). A received signal strength (EUTRA CarrierRSSI) indicates a strength of the total received signal power, and themeasurement bandwidth is the same as the system bandwidth. N is thenumber of Resource Block resource blocks (RBs) for the measuredbandwidth of the received signal strength (EUTRA Carrier RSSI). Thenumber of maximum report cells (maxReportCells) indicates the maximumnumber of cells included in the measurement report. The report interval(reportInterval) is used for the periodical reporting or the eventtriggered periodic reporting and is reported periodically at eachinterval indicated by the report interval (reportInterval). The reportamount (reportAmount) specifies the number of times to perform theperiodical reporting, if necessary.

Note that threshold parameters and offset parameters (a1_Threshold,a2_Threshold, a3_Offset, a4_Threshold, a5_Threshold1, a5_Threshold2,a6_Offset, c1_Threshold, and c2_Offset) utilized in the event triggeredcriteria described below are notified to the terminal apparatus 2together with the event identifier (eventId) in the report configurationEUTRA (reportConfigEUTRA).

Event Triggered Criteria

Multiple event triggered criteria are defined for performing themeasurement report, and each criterion has an entering condition and aleaving condition. In other words, the terminal apparatus 2 thatsatisfies the entering condition for the event specified by the basestation apparatus 3 transmits a measurement report to the base stationapparatus 3. In a case that the terminal apparatus 2 that satisfies theleaving condition for the event specified by the base station apparatus3 is configured by the base station apparatus 3 to trigger the reportingin a case that the leaving condition is satisfied (in a case thatreportOnLeave is included in the reporting configuration), the terminalapparatus 2 transmits a measurement report to the base station apparatus3. The entering conditions and leaving conditions for each event are asbelow.

Event A1

Even A1 entering condition: Ms−Hys>a1_Threshold Event A1 leavingcondition: Ms+Hys<a1_Threshold

Event A2

Event A2 entering condition: Ms−Hys<a2_Threshold Event A2 leavingcondition: Ms+Hys>a2_Threshold

Event A3

Event A3 entering condition: Mn+Ofn+Ocn−Hy s>Ms+Ofs+Ocs+a3_Offset EventA3 leaving condition: Mn+Ofn+Ocn+Hys<Ms+Ofs+Ocs+a3_Offset

Event A4

Event A4 entering condition: Mn+Ofn+Ocn−Hys>a4_Threshold Event A4leaving condition: Mn+Ofn+Ocn+Hys<a4_Threshold

Event A5

Event A5 entering condition: Ms−Hys<a5_Threshold1,Mn+Ofn+Ocn−Hys>a5_Threshold2 Event A5 leaving condition:Ms+Hys>a5_Threshold1, Mn+Ofn+Ocn+Hys<a5_Threshold2

Event A6

Event A6 entering condition: Mn+Ocn−Hys>Ms+Ocs+a6_Offset Event A6leaving condition: Mn+Ocn+Hys<Ms+Ocs+a6_Offset

Event C1

Event C1 entering condition: Mcr+Ocr−Hys>c1_Threshold Event C1 leavingcondition: Mcr+Ocr+Hys>c1_Threshold

Event C2

Event C2 entering condition: Mcr+Ocr−Hys>Mref+Oref+c2_Offset Event C2leaving condition: Mcr+Ocr+Hys>Mref+Oref+c2_Offset

Here, Ms is a measurement result for the serving cell (not taking intoaccount cell-specific measurement offset values). Mn is a measurementresult for the neighbour cell. Mcr is a measurement result for theCSI-RS resource (not taking into account any measurement offset values).Mref is a measurement result of the reference CSI-RS resource (nottaking into account any measurement offset values). The reference CSI-RSresource is defined as c2-RefCSI-RS notified by the measurement objectfor EUTRA (measObjectEUTRA). Hys is a hysteresis parameter for atargeted event.

Ofn is a frequency-specific measurement offset value for a frequency ofthe neighbor cell. Ofn corresponds to the offset frequency (offsetFreq)of the measurement object for EUTRA (measObjectEUTRA). In a case of theintra-frequency measurement, Ofn is the same as Ofs. In a case of theinter-frequency measurement, Ofn is the offset frequency (offsetFreq)included in the measurement object for EUTRA (measObjectEUTRA)corresponding to the downlink frequency different from the serving cell.

Ocs is a cell-specific measurement offset value for the neighbor cell.Ocn corresponds to the cell-specific offset (cellIndividualOffset) ofthe measurement object for EUTRA (measObjectEUTRA). In a case that Ocnis not configured, the measurement offset value is set to zero. In thecase of the intra-frequency measurement, Ocn is the cell-specific offset(cellIndividualOffset) included in the measurement object for EUTRA(measObjectEUTRA) corresponding to the downlink frequency the same asthe serving cell. In the case of the inter-frequency measurement, Ocn isthe cell-specific offset (cellIndividualOffset) included in themeasurement object for EUTRA (measObjectEUTRA) corresponding to thedownlink frequency different from the serving cell.

Ocr is a CSI-RS specific measurement offset value. Ocr corresponds to aCSI-RS specific offset (csi-RS-IndividualOffset) in the measurementobject for EUTRA (measObjectEUTRA) associated with the frequency of theCSI-RS resource. In a case that Ocr is not configured, the measurementoffset value is set to zero.

Ofs is a frequency-specific offset value for a frequency of the servingcell. Ofs corresponds to the offset frequency (offsetFreq) of themeasurement object for EUTRA (measObjectEUTRA).

Ocs is a cell-specific measurement offset value for the serving cell.Ocs is included in the cell-specific offset (cellIndividualOffset) ofthe measurement object for EUTRA (measObjectEUTRA) of the frequency ofserving cell.

a1_Threshold is a threshold parameter used for the event A1.a2_Threshold is a threshold parameter used for the event A2. a3_Offsetis an offset parameter used for the event A3. a4_Threshold is athreshold parameter used for the event A4. a5_Threshold 1 anda5_Threshold 2 are threshold parameters used for the event A5. a6_Offsetis an offset parameter used for the event A6. c1_Threshold is athreshold parameter used for the event C1. c2_Offset is an offsetparameter used for the event C2.

The terminal apparatus 2 generates each event by the measurement resultMs of the serving cell and the measurement result Mn of the neighborcell. In a case that the measurement result Ms of the serving cell afterthe parameters are applied thereto is better than the thresholda1_Threshold, then event A1 occurs, and in a case of being worse thanthe threshold a2_Threshold, the event A2 occurs. In a case that themeasurement result Mn of the neighbor cell after the parameters areapplied thereto is better than the serving cell measurement result Msand the offset a3_Offset, the event A3 occurs, and in a case that themeasurement result Mn of the neighbor cell after the parameters areapplied thereto is better than the threshold a4_Threshold, the event A4occurs. In a case that the measurement result Ms of the serving cellafter the parameters are applied thereto is worse than the thresholda5_Threshold1 and the measurement result Mn of the neighbor cell afterthe parameters are applied thereto is better than the thresholda5_Threshold2, the event A5 occurs.

In the reporting configuration InterRAT (reportConfigInterRAT), which isa Reporting configuration for RAT other than EUTRA, multiple triggeringcriteria for events that are utilized for reporting measurements in theRAT other than EUTRA are defined. For example, in a case that themeasurement result of the neighbor cell (other RAT) after the parametersare applied thereto is better than the threshold b1_Threshold configuredfor each RAT, the event B1 occurs. In a case that the measurement resultof the PCell after the parameters are applied thereto is worse than thethreshold b2_Threshold1 and the measurement result of the neighbor cell(other RAT) after the parameters are applied thereto is better than thethreshold b2_Threshold2 set for each RAT, the event B2 occurs.

Note that the base station apparatus 3 may give or may not give noticeof the serving cell quality threshold (s-Measure). In a case that thebase station apparatus 3 gives notice of the serving cell qualitythreshold (s-Measure), the terminal apparatus 2, and that the quality ofthe serving cell (RSRP value) is lower than the serving cell qualitythreshold (s-Measure), performs the neighbor cell measurement and theevent evaluation (of whether or not the event triggered criteria aresatisfied, also referred to as Reporting criteria evaluation). On theother hand, in a case that the base station apparatus 3 does not givenotice of the serving cell quality threshold (s-Measure), the terminalapparatus 2 performs the neighbor cell measurement and the eventevaluation regardless of the quality (RSRP value) of the serving cell.

Measurement Result

The terminal apparatus 2 that satisfies the event triggered criteriatransmits a Measurement report to the base station apparatus 3. TheMeasurement report includes a Measurement result.

The Measurement result includes a measurement identifier (measId), aserving cell measurement result (measResultServing), and a EUTRAmeasurement result list (measResultListEUTRA). Here, the EUTRAmeasurement result list (measResultListEUTRA) includes a physical cellidentifier (physicalCellIdentity) and a EUTRA cell measurement result(measResultEUTRA).

Here, the measurement identifier (measId) is an identifier utilized inthe link between the measurement object identifier (measObjectId) andthe reporting configuration identifier (reportConfigId) as describedabove. The serving cell measurement result (measResultServing) is ameasurement result for serving cell, and reports the results of both thereference signal received power (RSRP) and the reference signal receivedquality (RSRQ) for the serving cell. The measurement result for theserving cell is always included in the measurement result. The physicalcell identifier (physicalCellIdentity) is also utilized to identify thecell. The EUTRA cell measurement result (measResultEUTRA) is themeasurement result for the EUTRA cell. The measurement result of theneighbor cell is included only at the occurrence of the associatedevent.

The NR measurement may use a measurement configuration and measurementreport scheme equivalent to LTE. The NR Measurement configurationmessage may include a measurement identifier (measId), Measurementobject(s), addition and/or modification and/or deletion of Reportingconfiguration(s), a quantity configuration (quantityConfig), ameasurement gap configuration (measGapConfig), a serving cell qualitythreshold (s-Measure), and the like.

The measurement object NR (measObjectNR) may include some or all of NRcarrier frequency information (eutra-CarrierInfo), a measurementbandwidth (measurementBandwidth), offset frequency (offsetFreq),information on a neighbor cell list (neighbour cell list), andinformation on a black list.

A reporting configuration NR (reportConfigNR) may include information onthe event triggered reporting. The event triggered criteria may includeat least events that are equivalent to the events A1 to A6 of LTE.

The reference signal received power (RSRP) may be replaced with thesynchronization signal received power (SSRP) in a case that asynchronization signal is used for the measurement. Similarly, thereference signal received quality (RSRQ) may be replaced with thesynchronization signal reception quality (SSRQ) in the case that asynchronization signal is used for the measurement.

An example of the NR measurement is described below. Note thatinformation included in a message and/or a structure of the message areexamples and are not limited thereto.

The base station apparatus 3 uses an RRC connection reconfiguration(RRCConnectionReconfiguration) message of the RRC signaling (radioresource control signal) to transmit a Measurement configuration messageto the terminal apparatus 2. The terminal apparatus 2 configures systeminformation included in the Measurement configuration message, and inaccordance with the notified system information, performs measurement,event evaluation, and measurement report for a serving cell and aneighbor cell (including a listed cell and/or a detected cell). Thelisted cell is a cell that is listed within a Measurement object (a cellnotified as a neighbor cell list by the base station apparatus 3 to theterminal apparatus 2), and the detected cell is a cell that is detectedby the terminal apparatus 2 on a frequency indicated by the Measurementobject, but is not listed within the Measurement object (a cell detectedby the terminal apparatus 2 itself and not notified as a neighbor celllist).

The measurement includes three types, intra-frequency measurements,inter-frequency measurement, and inter-radio access technologymeasurement (inter-RAT measurement). The intra-frequency measurementsare a measurement at a downlink frequency in the serving cell. Theinter-frequency measurements are a measurement at a frequency differentfrom the downlink frequency in the serving cell. The inter-RATmeasurements are a measurement using a radio technology (e.g. EUTRA,UTRA, GERAN, CDMA2000, etc.) different from the radio technology in theserving cell (e.g. NR).

The Measurement configuration message includes a measurement identifier(measId), Measurement object(s), addition and/or modification and/ordeletion of Reporting configuration(s), a quantity configuration(quantityConfig), a measurement gap configuration (measGapConfig), aserving cell quality threshold (s-Measure), and the like.

Quantity Configuration (quantityConfig)

The quantity configuration (quantityConfig) may specify a layer-3filtering coefficient (L3 filtering coefficient) in a case that theMeasurement object is NR or EUTRA. The layer-3 filtering coefficient (L3filtering coefficient) specifies a ratio between the latest measurementresult and the past measurement result. The filtering result is used forthe event evaluation in the terminal apparatus 2.

Measurement Gap Configuration (measGapConfig)

The measurement gap configuration (measGapConfig) is utilized toconfigure a measurement gap pattern or control activation/deactivationof a measurement gap. In the measurement gap configuration(measGapConfig), the gap pattern, a start system frame (startSFN), and astart subframe number (startSubframeNumber) are notified as informationfor activating the measurement gap. The gap pattern specifies whichpattern to use as a measurement gap. The start system frame (startSFN)specifies a System Frame Number (SFN) where the measurement gap starts.The start subframe number (startSubframeNumber) specifies a subframenumber where the measurement gap starts. The measurement gapconfiguration may be configured independently for each cell or for eachcell group.

Serving Cell Quality Threshold (s-Measure)

The serving cell quality threshold (s-Measure) represents a thresholdfor the quality of the serving cell, and is used to control whether theterminal apparatus 2 needs to perform measurement. The serving cellquality threshold (s-Measure) is configured as a value for the referencesignal received power (RSRP) or the synchronization signal receivedpower (SSRP).

Measurement Identifier (measId)

Here, the measurement identifier (measId) is utilized to link theMeasurement object and the Reporting configuration, and specifically, tolink a measurement object identifier (measObjectId) and a reportingconfiguration identifier (reportConfigId). The measurement identifier(measId) is associated with one measurement object identifier(measObjectId) and one reporting configuration identifier(reportConfigId). The Measurement configuration message can makeaddition, modification, and deletion with respect to the relationshipbetween the measurement identifier (measId), the Measurement object, andthe Reporting configuration.

measObjectToRemoveList is a command to delete a specified measurementobject identifier (measObjectId) and a Measurement object correspondingto the specified measurement object identifier (measObjectId). At thistime, all the measurement identifiers (measIds) associated with thespecified measurement object identifier (measObjectId) are deleted. Thiscommand can simultaneously specify multiple measurement objectidentifiers (measObjectIds).

measObjectToAddModifyList is a command to modify a specified measurementobject identifier (measObjectId) to a specified Measurement object, orto add a specified measurement object identifier (measObjectId) and aspecified Measurement object. This command can simultaneously specifymultiple measurement object identifiers (measObjectIds).

reportConfigToRemoveList is a command to delete a specified reportingconfiguration identifier (reportConfigId) and a Reporting configurationcorresponding to the specified reporting configuration identifier(reportConfigId). At this time, all the measurement identifiers(measIds) associated with the specified reporting configurationidentifier (reportConfigId) are deleted. This command can simultaneouslyspecify multiple reporting configuration identifiers (reportConfigIds).

reportConfigToAddModifyList is a command to modify a specified reportingconfiguration identifier (reportConfigId) to a specified Reportingconfiguration, or to add a specified reporting configuration identifier(reportConfigId) and a specified Reporting configuration. This commandcan simultaneously specify multiple reporting configuration identifiers(reportConfigIds).

measIdToRemoveList is a command to delete the specified measurementidentifier (measId). At this time, the measurement object identifier(measObjectId) and the reporting configuration identifier(reportConfigId) associated with the specified measurement identifier(measId) are maintained without being deleted. This command cansimultaneously specify multiple measurement identifiers (measIds).

measIdToAddModifyList is a command to modify a specified measurementidentifier (measId) to be associated with a specified measurement objectidentifier (measObjectId) and a specified reporting configurationidentifier (reportConfigId), or to associate a specified measurementobject identifier (measObjectId) and a specified reporting configurationidentifier (reportConfigId) with a specified measurement identifier(measId) to add the specified measurement identifier (measId). Thiscommand can simultaneously specify multiple measurement identifiers(measIds).

Measurement Objects

The Measurement object is specified for each RAT and frequency. TheReporting configuration includes a specification for NR and aspecification for the RAT other than NR.

The Measurement object includes a measurement object NR (measObjectNR),a measurement object EUTRA (measObjectEUTRA), a measurement object UTRA(measObjectUTRA), a measurement object GERAN (measObjectGERAN), ameasurement object CDMA2000 (measObjectCDMA2000), a measurement objectWLAN (measObjectWLAN), and the like which are associated with themeasurement object identifier (measObjectId).

The measurement object identifier (measObjectId) is an identifier usedto identify configurations of Measurement objects. The configuration ofthe Measurement object is specified for each Radio Access Technology(RAT) and for each frequency as described above. The Measurement objectis otherwise specified for NR, EUTRA, UTRA, GERAN, CDMA2000. Themeasurement object NR (measObjectNR), which is a Measurement object forNR, specifies information to be applied to a neighbor cell of NR. Any ofthe measurement objects NR (measObjectNRs) that has a differentfrequency is treated as a different Measurement object, and assignedwith another measurement object identifier (measObjectId).

The measurement object NR (measObjectNR) may include some or all of NRcarrier frequency information (nr-CarrierInfo), a measurement bandwidth(measurementBandwidth), offset frequency (offsetFreq), information on aneighbor cell list (neighbour cell list), and information on a blacklist.

Next, information included in the measurement object NR (measObjectNR)will be described. The NR carrier frequency information (nr-CarrierInfo)specifies a carrier frequency to be measured. The measurement bandwidth(measurementBandwidth) indicates a measurement bandwidth common to allneighbor cells operating at the carrier frequency to be measured. Theoffset frequency (offsetFreq) indicates a measurement offset value to beapplied at the frequency to be measured.

The information on a neighbor cell list (neighbour cell list) includesinformation regarding event evaluations and neighbor cells to be subjectto measurement report. The information on the neighbor cell list(neighbour cell list) includes a physical cell identifier (physical cellID), a cell-specific offset (cellIndividualOffset, indicating ameasurement offset value applied to the neighbor cell), and the like. Inthe case of the NR, this information may be used as information foradding, modifying, or deleting the neighbor cell list (neighbour celllist) which the terminal apparatus 2 has already acquired from thebroadcast information (broadcast system information).

The information on a black list includes information regarding eventevaluations and neighbor cells not to be subject to measurement report.The information on the black list includes a physical cell identifier(physical cell ID) and the like. In the case of the NR, this informationmay be used as information for adding, modifying, or deleting the blackcell list (black listed cell list) which the terminal apparatus 2 hasalready acquired from the broadcast information.

Reporting Configurations

The Reporting configuration includes a report configuration NR(reportConfigNR) associated with a reporting configuration identifier(reportConfigId), and the like.

The reporting configuration identifier (reportConfigId) is an identifierused to identify a Reporting configuration related to the measurement.The Reporting configuration related to the measurement include aspecification for the NR and a specification for the RAT other than theNR (EUTRA, UTRA, GERAN, CDMA2000). The reporting configuration NR(reportConfigNR), which is a Reporting configuration for the NR,specifies triggering criteria of an event used for measurement report inthe NR.

The reporting configuration NR (reportConfigNR) may include some or allof an event identifier (eventId), a trigger quantity (triggerQuantity),a hysteresis, a trigger time (timeToTrigger), a report quantity(reportQuantity), the number of maximum report cells (maxReportCells), areport interval (reportInterval), and a report amount (reportAmount).

Next, the reporting configuration NR (reportConfigNR) will be described.The event identifier (eventId) is used to select criteria related to anevent triggered reporting. Here, the event triggered reporting refers toa method for reporting a measurement in a case that the event triggeredcriteria are satisfied. Besides, there is an event triggered periodicreporting in which the measurement is reported by a prescribed number oftimes at a constant interval in a case that the event triggered criteriaare satisfied.

A least six types described later are specified as an event triggeredcriterion. In a case that the event triggered criteria specified by theevent identifier (eventId) are satisfied, the terminal apparatus 2performs a measurement report on the base station apparatus 3. Thetrigger quantity (triggerQuantity) is a quantity utilized to evaluatethe event triggered criteria. That is, a synchronization signal receivedpower (SSRP) or a synchronization signal reception quality (SSRQ) isspecified. That is, the terminal apparatus 2 measures the downlinkreference signal by use of a quantity specified by the trigger quantity(triggerQuantity) to determine whether or not the event trigged criteriaspecified by the event identifier (eventId) are satisfied. Thehysteresis is a parameter utilized in the event triggered criteria. Thetrigger time (timeToTrigger) indicates a period in which the eventtriggered criteria should be met. The report quantity (reportQuantity)indicates a quantity reported in the measurement report. Here, thequantity specified by the trigger quantity (triggerQuantity), or thesynchronization signal received power (SSRP) or the synchronizationsignal reception quality (SSRQ) are specified. Here, the synchronizationsignal reception quality (SSRQ) is a ratio expressed by (N*SSRP)/(NRCarrier RSSI). A received signal strength (NR Carrier RSSI) indicates astrength of the total received signal power, and the measurementbandwidth is the same as the system bandwidth. N is the number ofResource Block resource blocks (RBs) for the measured bandwidth of thereceived signal strength (NR Carrier RSSI). The number of maximum reportcells (maxReportCells) indicates the maximum number of cells included inthe measurement report. The report interval (reportInterval) is used forthe periodical reporting or the event triggered periodic reporting andis reported periodically at each interval indicated by the reportinterval (reportInterval). The report amount (reportAmount) specifiesthe number of times to perform the periodical reporting, if necessary.

Note that threshold parameters and offset parameters (a1_Threshold,a2_Threshold, a3_Offset, a4_Threshold, a5_Threshold1, a5_Threshold2,a6_Offset) utilized in the event triggered criteria described below arenotified to the terminal apparatus 2 together with the event identifier(eventId) in the reporting configuration NR (reportConfigNR).

Event Triggered Criteria

Multiple event triggered criteria are defined for performing themeasurement report, and each criterion has an entering condition and aleaving condition. In other words, the terminal apparatus 2 thatsatisfies the entering condition for the event specified by the basestation apparatus 3 transmits a measurement report to the base stationapparatus 3. In a case that the terminal apparatus 2 that satisfies theleaving condition for the event specified by the base station apparatus3 is configured by the base station apparatus 3 to trigger the reportingin a case that the leaving condition is satisfied (in a case thatreportOnLeave is included in the reporting configuration), the terminalapparatus 2 transmits a measurement report to the base station apparatus3. The entering conditions and leaving conditions for each event are asbelow.

Event A1

Even A1 entering condition: Ms−Hys>a1_Threshold Event A1 leavingcondition: Ms+Hys<a1_Threshold

Event A2

Event A2 entering condition: Ms−Hys<a2_Threshold Event A2 leavingcondition: Ms+Hys>a2_Threshold

Event A3

Event A3 entering condition: Mn+Ofn+Ocn−Hy s>Ms+Ofs+Ocs+a3_Offset EventA3 leaving condition: Mn+Ofn+Ocn+Hys<Ms+Ofs+Ocs+a3_Offset

Event A4

Event A4 entering condition: Mn+Ofn+Ocn−Hys>a4_Threshold Event A4leaving condition: Mn+Ofn+Ocn+Hys<a4_Threshold

Event A5

Event A5 entering condition: Ms−Hys<a5_Threshold1,Mn+Ofn+Ocn−Hys>a5_Threshold2 Event A5 leaving condition:Ms+Hys>a5_Threshold1, Mn+Ofn+Ocn+Hys<a5_Threshold2

Event A6

Event A6 entering condition: Mn+Ocn−Hys>Ms+Ocs+a6_Offset Event A6leaving condition: Mn+Ocn+Hys<Ms+Ocs+a6_Offset

Here, Ms is a measurement result for the serving cell (not taking intoaccount cell-specific measurement offset values). Mn is a measurementresult for the neighbor cell (neighbour cell). Hys is a hysteresisparameter for a targeted event.

Ofn is a frequency-specific measurement offset value for a frequency ofthe neighbor cell. Ofn corresponds to the offset frequency (offsetFreq)of the measurement object NR (measObjectNR). In a case of theintra-frequency measurement, Ofn is the same as Ofs. In a case of theinter-frequency measurement, Ofn is the offset frequency (offsetFreq)included in the measurement object NR (measObjectNR) corresponding tothe downlink frequency different from the serving cell.

Ocn is a cell-specific measurement offset value for the serving cell.Ocn corresponds to the cell-specific offset (cellIndividualOffset) ofthe measurement object NR (measObjectNR). In a case that Ocn is notconfigured, the measurement offset value is set to zero. In the case ofthe intra-frequency measurement, Ocn is the cell-specific offset(cellIndividualOffset) included in the measurement object NR(measObjectNR) corresponding to the downlink frequency the same as theserving cell. In the case of the inter-frequency measurement, Ocn is thecell-specific offset (cellIndividualOffset) included in the measurementobject for EUTRA (measObjectEUTRA) corresponding to the downlinkfrequency different from the serving cell.

Ofs is a frequency-specific offset value for a frequency of the servingcell. Ofs corresponds to the offset frequency (offsetFreq) of themeasurement object NR (measObjectNR).

Ocs is a cell-specific measurement offset value for the serving cell.Ocs is included in the cell-specific offset (cellIndividualOffset) ofthe measurement object NR (measObjectNR) of the frequency of servingcell.

a1_Threshold is a threshold parameter used for the event A1.a2_Threshold is a threshold parameter used for the event A2. a3_Offsetis an offset parameter used for the event A3. a4_Threshold is athreshold parameter used for the event A4. a5_Threshold 1 anda5_Threshold 2 are threshold parameters used for the event A5. a6_Offsetis an offset parameter used for the event A6.

The terminal apparatus 2 generates each event by the measurement resultMs of the serving cell and the measurement result Mn of the neighborcell. In a case that the measurement result Ms of the serving cell afterthe parameters are applied thereto is better than the thresholda1_Threshold, then event A1 occurs, and in a case of being worse thanthe threshold a2_Threshold, the event A2 occurs. In a case that themeasurement result Mn of the neighbor cell after the parameters areapplied thereto is better than the serving cell measurement result Msand the offset a3_Offset, the event A3 occurs, and in a case that themeasurement result Mn of the neighbor cell after the parameters areapplied thereto is better than the threshold a4_Threshold, the event A4occurs. In a case that the measurement result Ms of the serving cellafter the parameters are applied thereto is worse than the thresholda5_Threshold1 and the measurement result Mn of the neighbor cell afterthe parameters are applied thereto is better than the thresholda5_Threshold2, the event A5 occurs.

In the Reporting configuration InterRAT (reportConfigInterRAT), which isa reporting configuration for RAT other than NR, the triggering criteriafor events that are utilized for reporting measurements in the RAT otherthan NR may be defined. For example, in a case that the measurementresult of the neighbor cell (other RAT) after the parameters are appliedthereto is better than the threshold b1_Threshold set for each RAT, theevent B1 may be generated. In a case that the measurement result of thePCell after the parameters are applied thereto is worse than thethreshold b2_Threshold1 and the measurement result of the neighbor cell(other RAT) after the parameters are applied thereto is better than thethreshold b2_Threshold2 set for each RAT, the event B2 may be generated.

Note that the base station apparatus 3 may give or may not give noticeof the serving cell quality threshold (s-Measure). In a case that thebase station apparatus 3 gives notice of the serving cell qualitythreshold (s-Measure), the terminal apparatus 2, and that the quality ofthe serving cell (RSRP value or SSRP value) is lower than the servingcell quality threshold (s-Measure), performs the neighbor cellmeasurement and the event evaluation (of whether or not the eventtriggered criteria are satisfied, also referred to as Reporting criteriaevaluation). On the other hand, in a case that the base stationapparatus 3 does not give notice of the serving cell quality threshold(s-Measure), the terminal apparatus 2 performs the neighbor cellmeasurement and the event evaluation regardless of the quality (RSRPvalue or SSRP value) of the serving cell.

Measurement Result

The terminal apparatus 2 that satisfies the event triggered criteriatransmits a Measurement report to the base station apparatus 3. TheMeasurement report includes a Measurement result.

The Measurement result includes a measurement identifier (measId), aserving cell measurement result (measResultServing), and an NRmeasurement result list (measResultListNR). Here, the measResultListNRincludes a physical cell identity (physicalCellIdentity) and an NR cellmeasurement result (measResultNR).

Here, the measurement identifier (measId) is an identifier utilized inthe link between the measurement object identifier (measObjectId) andthe reporting configuration identifier (reportConfigId) as describedabove. The serving cell measurement result (measResultServing) is ameasurement result for serving cell, and may report the results of boththe reference signal received power (SSRP) and the reference signalreceived quality (SSRQ) for the serving cell. The physical cellidentifier (physicalCellIdentity) is also utilized to identify the cell.The NR cell measurement result (measResultNR) is the measurement resultfor the NR cell. The measurement result of the neighbor cell is includedonly at the occurrence of the associated event.

Next, a description is given of an example of, with a cell (first cell)of a first base station apparatus 3 being the primary cell of the mastercell group, an operation of adding a cell (second cell) of a second basestation apparatus 3 as a cell of the secondary cell group (e.g., primarysecondary cell (PSCell)) in a state in which the terminal apparatus 2 ina connected state or an inactive state is in communication. The firstbase station apparatus 3 is also referred to as a Master eNB (MeNB) or aMaster Node (MN). The second base station apparatus 3 is also referredto as a Secondary eNB (SeNB) or a Secondary Node (SN).

A case is described where a cell of the MCG including the first cell isa cell of LTE and a cell of the SCG including the second cell is a cellof LTE.

The first base station apparatus 3 configures, via the MCG SRB (MCGSRB), the measurement object EUTRA including the frequency of the cellthat is a candidate for the primary secondary cell, and the reportingconfiguration EUTRA to the terminal apparatus 2 (step S71). The terminalapparatus 2 starts the measurement, based on the configured measurementobject EUTRA and reporting configuration EUTRA (step S72), and reportsthe measurement report to the base station apparatus 3 via the MCG SRB,based on the triggered criteria of the reporting configuration EUTRA(step S73). The base station apparatus 3 selects the primary secondarycell, based on the measurement report (step S74). Further, the basestation apparatus 3 may configure an additional measurementconfiguration to the terminal apparatus 2 to make the terminal apparatus2 report the Cell Global Identity (CGI) for identifying a cell ofinterest. Note that the base station apparatus 3 may select the primarysecondary cell by measures other than those described above.

The first base station apparatus 3 transmits, to the base stationapparatus 3 (second base station apparatus 3) of the selected cell, aSeNB Addition Request message for requesting allocation of a radioresource (step S75). The SeNB Addition Request may include, asSCG-ConfigInfo, UE Capability, MCG radio resource configuration(radioResourceConfigDedMCG), MCG SCell information, and information onan SCG cell (PSCell and/or SCell) requested to be added which are usedfor reconfiguration by the SeNB. The MeNB may provide the most recentmeasurement result of the cell requested to be added. The MCG SCellinformation and the SCG cell information included in the SCG-ConfigInfomay include index (SCellIndex) information for identifying each cell.The MCG SCell information and the SCG cell information included in theSCG-ConfigInfo may include physical cell identifier information(physCellId) of the cell and downlink frequency information(dl-CarrierFreq) of the cell. In addition, an index (ServCellIndex) foridentifying all serving cells including the SCellIndex and an index ofthe PCell (index 0) may be defined.

The base station apparatus 3 receiving the SeNB Addition Request, in acase that the resource request is acceptable, configures a radioresource configuration to be allocated to the terminal apparatus 2 asSCG-Config, and transmits a SeNB Addition Request Acknowledge messageincluding the SCG-Config to the first base station apparatus 3 (stepS76).

The first base station apparatus 3 receiving the SeNB Addition RequestAcknowledge message, in case of endorsing the received radio resourceconfiguration, transmits an RRC connection reconfiguration messageincluding SCG radio resource configuration for the SCG-Config to theterminal apparatus 2 via an MCG SRB (step S77). The terminal apparatus 2receiving the RRC connection reconfiguration message applies a newconfiguration to itself, and in a case of successful application,transmits an RRC connection reconfiguration complete(RRCConnectionReconfigurationComplete) message to the first base stationapparatus 3 via an MCG SRB (step S78).

The first base station apparatus 3 receiving the RRC connectionreconfiguration complete message may notify the second base stationapparatus 3 that reconfiguration of the terminal apparatus 2 hassuccessfully completed.

The terminal apparatus 2 transmitting the RRC connection reconfigurationcomplete message performs synchronization with the PSCell of the secondbase station apparatus 3 and starts communication in the PSCell (stepS79). Note that the terminal apparatus 2 may perform synchronizationwith the PSCell of the second base station apparatus 3 beforetransmitting the RRC connection reconfiguration complete message.

The addition of the PSCell (SeNB) by the MeNB has been described above,but modification of the PSCell (SeNB) by the PCell can also be achievedby transmitting, by the MeNB, a SeNB Modification Request messageincluding the SCG-ConfigInfo to the SeNB, based on the measurementreport received from the terminal apparatus 2. Release of the PSCell(SeNB) by the PCell can also be achieved by transmitting, by the MeNB, aSeNB Release Request message to the SeNB, based on the measurementreport received from the terminal apparatus 2. Change of the PSCell(SeNB) by the PCell can also be achieved by transmitting, by the MeNB, aSeNB Addition Request message to the SeNB after the change and a SeNBRelease Request message to the SeNB before the change, based on themeasurement report received from the terminal apparatus 2.

A case is described where a cell of the MCG including the first cell isa cell of NR and a cell of the SCG including the second cell is a cellof NR. In this case, the MCG and the SCG may be configured with RRCmessages of NR. Parameters for the MCG and parameters for the SCG may beconfigured with RRC messages of NR using an MCG SRB. The parameters forthe MCG may be transmitted directly using an MCG SRB. The parameters forthe SCG may be transmitted directly using an SCG SRB. In this case, theterminal apparatus 2 may receive the reporting configuration for the SCGusing the SCG SRB and receive the reporting configuration for the MCGusing MCG SRB.

In this case, the PSCell can be added by a similar process, in theprocess of the case that a cell of the MCG is a cell of LTE and a cellof the SCG is a cell of LTE, by replacing the measurement object EUTRAand the reporting configuration EUTRA with the measurement object NR andthe reporting configuration NR, respectively, and therefore, a detaileddescription thereof is omitted.

A description will be given of a case of a certain configuration. Inthis case, a cell of the MCG including the first cell may be a cell ofLTE (E-UTRAN) and a cell of the SCG including the second cell may be acell of NR. Parameters for the MCG may be configured with the RRCmessages of EUTRAN, and parameters for the SCG may be configured withthe RRC messages of NR included in the RRC messages of EUTRAN. Theparameters for the MCG included in the RRC message of EUTRAN may betransmitted directly using an MCG SRB. The parameters for the SCGincluded in the RRC message of NR may be transmitted directly using anSCG SRB. In this case, the terminal apparatus 2 receives the reportingconfiguration for the SCG using the SCG SRB and receives the reportingconfiguration for the MCG using the MCG SRB.

The terminal apparatus 2 is configured with the measurement object NRincluding the frequency of the NR cell and the reporting configurationInterRAT from the first base station apparatus 3 via the MCG SRB. Thefrequency of the NR cell may be used to select the candidate for theprimary secondary cell. The terminal apparatus 2 starts the measurement,based on the configured measurement object NR and reportingconfiguration InterRAT, and reports the measurement report to the basestation apparatus 3 via the MCG SRB, based on the triggering criteria ofthe reporting configuration InterRAT. The base station apparatus 3selects the primary secondary cell, based on the measurement report.Further, the base station apparatus 3 may configure an additionalmeasurement configuration to the terminal apparatus 2 to make theterminal apparatus 2 report the Cell Global Identity (CGI) foridentifying a cell of interest. Note that the base station apparatus 3may select the primary secondary cell by measures other than thosedescribed above.

The first base station apparatus 3 (MN) transmits, to the base stationapparatus 3 (second base station apparatus 3, SN candidate) of theselected cell, an SN Addition Request message for requesting allocationof a radio resource. The SN Addition Request may include, asSCG-ConfigInfo, UE Capability, MCG radio resource configuration(radioResourceConfigDedMCG), current SCell configuration information forthe MCG (sCellToAddModListMCG), information on an SCG cell requested tobe added (sCellToAddModListSCG), and information on an SCG cellrequested to be released (sCellToReleaseListSCG) which are used forreconfiguration by the SN. The MN may provide the most recentmeasurement result of the cell requested to be added. The MCG SCellinformation and the SCG cell information included in the SCG-ConfigInfomay include index (SCellIndex) information for identifying each cell.The SCG-ConfigInfo may include information indicating a value or rangeof the SCellIndex that can be used in the SCG. This allows the SN toconfigure the SCellIndex independently from the MN without theSCellIndex overlapping those of the MCG. The information indicating avalue or range of the SCellIndex that can be used in the SCG may benotified from the MN to the SN through another message. Informationregarding the number of SCells used in the SCG may be notified from theSN to the MN. The MCG SCell information and the SCG cell informationincluded in the SCG-ConfigInfo may include physical cell identifierinformation (physCellId) of the cell and downlink frequency information(dl-CarrierFreq) of the cell. In addition, an index (ServCellIndex) foridentifying all serving cells including the SCellIndex and an index ofthe PCell (index 0) may be defined.

The base station apparatus 3 receiving the SN Addition Request, in acase that the resource request is acceptable, configures a radioresource configuration to be allocated to the terminal apparatus 2 asSCG-Config, and transmits an SN Addition Request Acknowledge messageincluding the SCG-Config to the first base station apparatus 3.

The first base station apparatus 3 receiving the SN Addition RequestAcknowledge message, in a case of endorsing the received radio resourceconfiguration, transmits an RRC connection reconfiguration messageincluding SCG radio resource configuration for the SCG-Config to theterminal apparatus 2 via an MCG SRB. The terminal apparatus 2 receivingthe RRC connection reconfiguration message applies a new configurationto itself, and in a case of successful application, transmits an RRCconnection reconfiguration complete message to the first base stationapparatus 3 via an MCG SRB.

The terminal apparatus 2 receiving the RRC connection reconfigurationmessage including the SCG radio resource configuration for theSCG-Config, in a case that an SCG SRB is configured, may transmit aresponse for the SCG radio resource configuration for the SCG-Config viaan SCG SRB. To be more specific, in a case that an SCG SRB is configuredand the SCG SRB is configured to be used for a response for theSCG-Config, the response for the SCG radio resource configuration forthe SCG-Config may be transmitted via the SCG SRB. For example, theterminal apparatus 2 receiving the RRC connection reconfigurationmessage including the SCG radio resource configuration for theSCG-Config applies a new configuration except for the SCG-Config toitself, and in a case of successful application, transmits an RRCconnection reconfiguration complete message to the first base stationapparatus 3 via an MCG SRB. The terminal apparatus 2 receiving the RRCconnection reconfiguration message including the SCG radio resourceconfiguration for the SCG-Config applies a new configuration of theSCG-Config to itself, and in a case of successful application, transmitsan SCG RRC connection reconfiguration complete message to the secondbase station apparatus 3 via an SCG SRB.

The first base station apparatus 3 receiving the RRC connectionreconfiguration complete message notifies the second base stationapparatus 3 that reconfiguration of the terminal apparatus 2 hassuccessfully completed.

The terminal apparatus 2 transmitting the RRC connection reconfigurationcomplete message performs synchronization with the PSCell of the secondbase station apparatus 3 and starts communication in the PSCell. Notethat the terminal apparatus 2 may perform synchronization with thePSCell of the second base station apparatus 3 before transmitting theRRC connection reconfiguration complete message.

The addition of the PSCell (SN) by the MN has been described above, butmodification of the PSCell (SN) by the PCell can also be achieved bytransmitting, by the MN, an SN Modification Request message includingthe SCG-ConfigInfo to the SN. Release of the PSCell (SN) by the PCellcan also be achieved by transmitting, by the MN, an SN Release Requestmessage to the SN. Change of the PSCell (SN) by the PCell can also beachieved by transmitting, by the MN, an SN Addition Request message tothe SN after the change and an SN Release Request message to the SNbefore the change.

The modification, release, and change of the PSCell (SN) by the SN willbe described.

For example, in a case that the MN and the SN directly configure themeasurement configurations to the terminal apparatus 2 via the MCG SRBand the SCG SRB, respectively, and receive the measurement reports fromthe terminal apparatus 2, the SN may be able to recognize that thePSCell required to be modified, released, or changed.

In a case that the PSCell required to be modified, the SN may transmitan SN Modification Required message including the SCG-Config to the MNto notify the MN of information required for SN modification. Based onthis information, the MN can perform the modification of the PSCell bythe MN. In the case that the configuration to the terminal apparatus 2(RRCConnectionReconfiguration) is successful, the MN may transmit an SNModification Confirm message to the SN.

In a case that the PSCell is required to be released, the SN maytransmit an SN Release Required message to the MN to notify the MN thatSN release is required. Based on this information, the MN can performthe release of the PSCell by MN. The MN may transmit an SN ReleaseConfirm message to the SN.

In a case that the PSCell is required to be changed accompanied by theSN being changed, the SN may transmit an SN Change Required messageincluding a part of the information of the SCG-ConfigInfo (e.g.,information on the SCG cell of the SN after changed(sCellToAddModListSCG) to the MN to notify the MN of informationrequired for SN change. Based on this information, the MN can transmitan SN Addition Request message to the SN after the change, and, in acase of successful addition request, can transmit an SN release messageto the SN before the change.

Next, a description is given of an example of, with a cell (first cell)of the first base station apparatus 3 (MN) being the primary cell of themaster cell group and a cell (second cell) of the second base stationapparatus 3 (SN) being the primary secondary cell of the secondary cellgroup, an operation of adding the SCell of the master cell group or thesecondary cell group in the state in which the terminal apparatus 2 in aconnected state or an inactive state is in communication. However, thisoperation is not limited to the purpose of adding the SCell of themaster cell group or the secondary cell group.

In a case that the MN adds the SCell in the MCG, SCellIndex that doesnot overlap SCellIndex already assigned to the MCG SCell or SCellIndexalready assigned to the SCG SCell is selected and assigned to an addedcell. The SCell configuration information for the MCG including theadded SCell may be included in the sCellToAddModListMCG of theSCG-ConfigInfo and notified to the SN.

A case is described that the SN adds the SCell in the SCG, and the SNAddition Request message which is previously received includes a list ofvalues of or a range of a value of the SCellIndex that can be used inthe SCG, with reference to FIG. 8. First, the list of values of or therange of a value of the SCellIndex that can be used in the SCG isnotified to the SN through the SN Addition Request message of a list ofSCellIndex values or a range of values that can be used in SCG (stepS801), and an SN addition procedure is completed by a procedure the sameas from step S76 to step S79 in FIG. 7 (step S802 to step S805). The SNselects the SCellIndex that does not overlap SCellIndex already assignedto the SCG SCell from the list of values or the range of a value, andassigns the selected SCellIndex to the added cell (step S806). The SCellconfiguration information for the SCG including the added SCell may beincluded in the SCG-ConfigInfo or scg-ConfigPartSCG of the SCG-Configand notified to the MN (step S807). The SN transmits an RRC connectionreconfiguration message including the SCell configuration information(such as an SCG RRC connection reconfiguration message) to the terminalapparatus 2 (step S808). The terminal apparatus 2 configured with theSCell transmits an RRC connection reconfiguration complete message (suchas an SCG RRC connection reconfiguration complete message) to the SN viaan SCG SRB (step S809). This can prevent Index duplication and canreduce signaling between the MN and the SN in adding the SCell. Notethat the transmission of the RRC connection reconfiguration message atof step S808 may be performed by the MN via an MCG SRB, and the terminalapparatus 2 may transmit the RRC connection reconfiguration completemessage to the MN via the MCG SRB at step S809. The list of values of orthe range of a value of the SCellIndex that can be used in the SCG maybe predetermined in specifications or the like.

A case is described that the SN adds the SCell in the SCG, and the SNAddition Request message which is previously received does not includethe list of values of or the range of a value of the SCellIndex that canbe used in the SCG, with reference to FIG. 9. The SN selects theSCellIndex that does not overlap SCellIndex already assigned to the MCGSCell or SCellIndex already assigned to the SCG SCell, and transmits anSN Modification Required message including information on the selectedSCellIndex to the MN (step S91). In a case that the SCellIndex which theMN receives from the SN overlaps another (MCG) SCell, the MN maytransmit an SN Modification Confirm messages including a new Index thatdoes not overlap other SCellIndex to the SN (step S92). The MN maytransmit the SN Modification Confirmation message without changing theSCellIndex to the SN even in a case that the SCellIndex does notoverlap. The information included in the SN Modified Confirmationmessage may be the SCG-ConfigInfo including the information on the addedSCell. Alternatively, the SN may not select the SCellIndex and notifyinformation other than the SCellIndex of the added SCell in the SNModification Required message (e.g., the physical cell identifier ordownlink carrier frequency information of the cell), with the Indexselected by the MN being the SCellIndex. The SN transmits an RRCconnection reconfiguration message including the SCell configurationinformation (such as an SCG RRC connection reconfiguration message) tothe terminal apparatus 2 via an SCG SRB (step S93). The terminalapparatus 2 configured with the SCell transmits an RRC connectionreconfiguration complete message (such as an SCG RRC connectionreconfiguration complete message) to the SN via the SCG SRB (step S94).This can prevent Index duplication and can reduce signaling between theMN and the SN in adding the SCell. Note that the transmission of the RRCconnection reconfiguration message at of step S93 may be performed bythe MN via an MCG SRB, and the terminal apparatus 2 may transmit the RRCconnection reconfiguration complete message to the MN via the MCG SRB atstep S94.

As described above, the configuration of the SCell added by the MNand/or SN is notified to the terminal apparatus 2 through the RRCconnection reconfiguration message. The RRC connection reconfigurationmessage may be configured from the MN in the case of for adding the MCGSCell. The RRC connection reconfiguration message may be configured fromthe MN or the SN in the case of adding the SCG SCell.

Note that in a case that the terminal apparatus 2 is configured, via theSCG SRB, with the Index the same as the SCellIndex configured via theMCG SRB, the terminal apparatus 2 may notify the MN that theconfiguration has failed through an SCG failure information(SCGFailureInformation) message using an MCG SRB. In the case that theterminal apparatus 2 is configured, via the SCG SRB, with the Index thesame as the SCellIndex configured via the MCG SRB, the terminalapparatus 2 may notify the SN that the configuration has failed throughan SCG reconfiguration failure (SCG RRCConnectionReconfigurationFailure)message using an SCG SRB.

Note that in a case that the terminal apparatus 2 is configured, via theMCG SRB, with the Index the same as the SCellIndex configured via theSCG SRB, the terminal apparatus 2 may overwrite with the configurationconfigured via the MCG SRB, and notify the MN that the configuration hasfailed through an SCG failure information (SCGFailureInformation)message using an MCG SRB. In a case that the terminal apparatus 2 isconfigured, via the MCG SRB, with the Index the same as the SCellIndexconfigured via the SCG SRB, the terminal apparatus 2 may overwrite withthe configuration configured via the MCG SRB, and notify the SN that theconfiguration has failed through an SCG reconfiguration failure (SCGRRCConnectionReconfigurationFailure) message using an SCG SRB.

Next, a description is given of an example of, with a cell (first cell)of the first base station apparatus 3 (MN) being the primary cell of themaster cell group and a cell (second cell) of the second base stationapparatus 3 (SN) being the primary secondary cell of the secondary cellgroup, an operation of modifying the SCell of the master cell group orthe secondary cell group in the state in which the terminal apparatus 2in a connected state or an inactive state is in communication. However,this operation is not limited to the purpose of modifying the SCell ofthe master cell group or the secondary cell group.

In a case that the MN modifies the SCell in the MCG, the SCellconfiguration information for the MCG including the modified SCell maybe included in the sCellToAddModListMCG of the SCG-ConfigInfo andnotified from the MN to the SN.

In a case that the SN modifies the SCell in the SCG, the SCellconfiguration information for the SCG including the modified SCell maybe included in the SCG-ConfigInfo or scg-ConfigPartSCG of the SCG-Configand notified from the SN to the MN.

As described above, the configuration of the SCell modified by the MNand/or the SN is notified to the terminal apparatus 2 through the RRCconnection reconfiguration message. The RRC connection reconfigurationmessage may be configured from the MN via an MCG SRB in the case of foradding the MCG SCell. The RRC connection reconfiguration message may beconfigured from the MN or the SN via a respective SRB (MCG SRB or SCGSRB) in the case of adding the SCG SCell.

Next, a description is given of an example of, with a cell (first cell)of the first base station apparatus 3 (MN) being the primary cell of themaster cell group and a cell (second cell) of the second base stationapparatus 3 (SN) being the primary secondary cell of the secondary cellgroup, an operation of releasing the SCell of the master cell group orthe secondary cell group in the state in which the terminal apparatus 2in a connected state or an inactive state is in communication. However,this operation is not limited to the purpose of releasing the SCell ofthe master cell group or the secondary cell group.

In a case that the MN releases the SCell in the MCG, the SCellconfiguration information for the MCG including the released SCell maybe included in the sCellToAddModListMCG of the SCG-ConfigInfo andnotified from the MN to the SN.

In a case that the SN releases the SCell in the SCG, the SCellconfiguration information for the SCG including the released SCell maybe included in the SCG-ConfigInfo or scg-ConfigPartSCG of the SCG-Configand notified from the SN to the MN.

Alternatively, in the case that the SN releases the SCell in the SCG,information on the released SCellIndex is included in an SN ModificationRequired message and transmitted to the MN. The MN may transmit an SNModification Confirm message including the SCG-ConfigInfo which isreceived from the SN and includes the SCell information on the releasedSCell.

As described above, the configuration of the SCell released by the MNand/or the SN is notified to the terminal apparatus 2 through the RRCconnection reconfiguration message. The RRC connection reconfigurationmessage may be configured from the MN via an MCG SRB in the case of forreleasing the MCG SCell. The RRC connection reconfiguration message maybe configured from the MN or the SN via a respective SRB (MCG SRB or SCGSRB) in the case of releasing the SCG SCell.

An example of the RRC connection reconfiguration message will bedescribed using FIG. 10.

As illustrated in FIG. 10, the RRC connection reconfiguration messagemay include some or all of (10A) rrc-TransactionIdentifier, (10B)measConfig, (10C) mobilityControlInfo, (10D) dedicatedInfoNASList, (10E)radioResourceConfigDedicated, (10F) securityConfigHO, (10G) otherConfig,(10H) fullConfig, (10I) sCellToReleaseList, (10J) sCellToAddModList, and(10K) systemInfomationBlockDedicated.

(10A) rrc-TransactionIdentifier is an element used to identify RRCprocedures (transactions) and has a value of an integer from 0 to 3, forexample. (10B) measConfig is information for configuring a measurementPerformed by the terminal apparatus 2 and may include a configuration ofa gap period for measurement. (10D) dedicatedInfoNASList is a list ofNAS layer information specific to the terminal apparatus 2 exchangedbetween the network and the terminal apparatus 2 and includes NAS layerinformation for each DRB, and the RRC layer transmits this informationto the higher layer (NAS layer) transparently. (10E)radioResourceConfigDedicated may include information used to configure,change, and/or release the SRB and DRB, information for changing a MAClayer configuration, information about a channel configuration for thephysical layer, and the like. (10F) securityConfigHO is a configurationfor security, and may include, for example, a configuration of anIntegrity Protection algorithm in AS layers of the SRB, a configurationof a Ciphering algorithm of the SRB and/or the DRB, and the like. (10H)fullConfig is information indicating whether or not a specific option isapplied to this RRC connection reconfiguration message, and the terminalapparatus 2 may apply a configuration included in a specific element ina case that (10H) fullConfig is included in the RRC connectionreconfiguration message. (10I) sCellToReleaseList and (10J)sCellToAddModList may include information used to add, modify, and/orrelease the secondary cell. (10K) systemInfomationBlockDedicated mayinclude a portion of the notification information for the target cell.

(10C) mobilityControlInfo includes parameters necessary for the mobilityby the network control (e.g., handover). (10C) mobilityControlInfo mayinclude some or all of targetPhysCellId, carrierFreq, carrierBandwidth,t304, newUE-Identity, radioResourceConfigCommon, andrach-ConfigDedicated. (10C) mobilityControlInfo may also include variousother information.

targetPhysCellId indicates an identifier of the target cell (e.g., aphysical cell identifier). carrierFreq indicates information on thefrequency used by the terminal apparatus 2 in the target cell.carrierBandwidth indicates information on the downlink and/or uplinkbandwidth of the target cell. t304 indicates a value of a timer for thehandover, and for example, the terminal apparatus 2 may perform thepredetermined process in a case that the handover is not successfullycompleted within a time indicated by the timer. newUE-Identity indicatesa new identifier (e.g., C-RNTI) of the terminal apparatus 2 in thetarget cell.

radioResourceConfigCommon includes information used to Specify commonradio resource configurations, such as random access parameters andstatic physical layer parameters.

rach-ConfigDedicated includes information used to specify individualrandom access parameters allocated to the terminal apparatus 2. Forexample, rach-ConfigDedicated may include some or all of informationexplicitly indicating the format or time/frequency resource of therandom access preamble, and/or information on numerologies used totransmit the preamble.

(10G) otherConfig includes some or all of the other configurations.

An example of the secondary cell group configuration (SCG-Configuration)included in the RRC connection reconfiguration message will be describedusing FIG. 11.

As illustrated in FIG. 11, the secondary cell group configuration mayinclude some or all of (11A) scg-ConfigPartMCG and (11B)scg-ConfigPartSCG.

(11A) scg-ConfigPartMCG is a configuration associated with also themaster cell group in a case that the secondary cell group configurationis configured, and may include, for example, information about updatingof key information and/or information about power of master cell groupsand secondary cell groups, and the like. (11B) scg-ConfigPartSCG is asecondary cell group configuration, and may include, for example, (12A)radioResourceConfigDedicatedSCG, pSCellToAddMod, (12C)sCellToAddModListSCG, (12D) sCellToReleaseListSCG, and/or (12E)mobilityControlInfoSCG, as illustrated in FIG. 12.

(12A) radioResourceConfigDedicatedSCG is a radio resource configurationspecific to the terminal apparatus 2 for the SCG, and may includeinformation for adding/changing the DRB, MAC layer configurationinformation, a timer configuration value, and/or constant information.(12B) pSCellToAddMod is addition/modification information of a cell tobe the PSCell, and may include index information for identifying theSCell (PSCell), an identifier of the cell (e.g., a physical cellidentifier or cell global identifier), downlink carrier frequencyinformation, a common radio resource configuration for the PSCell,and/or information on a radio resource configuration specific to theterminal apparatus 2 in the PSCell.

(12C) sCellToAddModListSCG is addition/modification information of acell to be the SCell of the secondary cell group and may include one ormore lists of SCell information. Furthermore, each piece of SCellinformation may include SCell index information for identifying theSCell, an identifier of the cell (e.g., a physical cell identifier or acell global identifier), downlink carrier frequency information, and/orinformation on a common radio resource configuration for the SCell.(12D) sCellToReleaseListSCG is information for releasing the SCell ofthe secondary cell group, and may include one or more lists of SCellindex information.

(12E) mobilityControlInfoSCG is information required to change thesecondary cell group, and may include an identifier assigned to theterminal apparatus 2 in the secondary cell group, information used tospecify the individual random access parameters allocated to theterminal apparatus 2, and/or information about a ciphering algorithm.

Note that the above message is an example, and the RRC connectionreconfiguration message may include information other than the above RRCconnection reconfiguration message, or may not include some pieces ofinformation on the RRC connection reconfiguration message. The RRCconnection reconfiguration message may be different from the above RRCconnection reconfiguration message in a structure, an informationelement name, or a parameter name.

Next, a description is given of an example of an operation ofconfiguring the measurement configuration from the MN and the SN to theterminal apparatus 2.

First, an example of the measurement configuration in a case that themeasurement objects of the MN and the SN are common will be describedusing FIG. 13 and FIG. 14.

In FIG. 13, the MN configures a measurement configuration including ameasurement object available in common with the SN to the terminalapparatus 2 via an MCG SRB (step S132). Prior to this, information onthe measurement object required by the SN may be notified to the MN(step S131). The information on the measurement object required by theSN may be notified through an SN Addition Request Acknowledge message oran SN Modification Request Acknowledge message or an SN AdditionRequired message or an SN Modification Required message or other RRCmessage.

With the MN being in the EUTRAN and the SN being in the NG-RAN, the MNmay use a EUTRAN RRC message (also referred to as an LTE RRC message ora EUTRA RRC message) and the SN may use an NG-RAN RRC message (alsoreferred to as an NR RRC message). NR is configured as the InterRATconfiguration in the EUTRAN RRC message, while EUTRA is configured asthe InterRAT configuration in the NG-RAN RRC message.

In a case that the measurement configuration is successful (for example,in a case of receiving the RRC connection reconfiguration completemessage from the terminal apparatus 2), the MN may notify the SN of theinformation on the measurement object (step S133).

The SN configures a measurement configuration not including ameasurement object to the terminal apparatus 2 via an SCG SRB (stepS134).

Here, an example of the measurement configuration configured in stepS132 and step S134 is illustrated in FIG. 14.

In FIG. 14, on the MN side, five measurement objects are configured forthe terminal apparatus 2, and two report configurations EUTRA(reportConfigEUTRAs) and one reportConfigInterRAT are configured.Combinations of these three reporting configurations and the measurementobjects respectively associated are configured with the measurementidentifiers. On the SN side, five measurement objects common to the MNare configured for the terminal apparatus 2, and three reportConfigNRsare configured. Combinations of these three reporting configurations andthe measurement objects respectively associated are configured with themeasurement identifiers.

At this time, as for the serving cell, the serving cell in themeasurement on the MN side may be only the cell of the MN (MCG cell), orthe cells of both the MN and the SN. For example, in a case that theserving cell in the measurement on the MN side is only the cell of theMN, Event A6 for the frequency of only the cell of the SN is notsupported in the measurement on the MN side. In other words, in a casewhere Event A6 is associated with a measurement object at the frequencyof only the cell of the SN, the terminal apparatus 2 does not considerthis configuration to be valid. In a case that the serving cell in themeasurement on the MN side is each of the cells of both the MN and theSN, Event A6 for the frequency of only the cell of the SN may besupported in the measurement on the MN side.

As for the serving cell, the serving cell in the measurement on the SNside may be only the cell of the SN (SCG cell), or the cells of both theMN and the SN. For example, in a case that the serving cell in themeasurement on the SN side is only the cell of the SN, Event A6 for thefrequency of only the cell of the MN is not supported in the measurementon the SN side. In other words, in a case where Event A6 is associatedwith a measurement object at the frequency of only the cell of the MN,the terminal apparatus 2 does not consider this configuration to bevalid. In a case that the serving cell in the measurement on the SN sideis each of the cells of both the MN and the SN, Event A6 for thefrequency of only the cell of the MN may be supported in the measurementon the MN side.

The measurement objects may be all different in the frequency.Alternatively, the frequency may be the same within the measObjectEUTRAor within the measObjectNR, and the frequencies may be different betweenthe measObjectEUTRA and the measObjectNR.

In a case that the terminal apparatus 2 configured with the abovemeasurement configuration satisfies the condition of the reportingconfiguration configured by the MN (or, configured via the MCG SRB)(step S135), the terminal apparatus 2 notifies the MN of the measurementresult (via the MCG SRB) (step S136), or in a case that the terminalapparatus 2 satisfies the condition of the reporting configurationconfigured by the SN (or, configured via the SCG SRB) (step S137), theterminal apparatus 2 notifies the SN of the measurement result (via theSCG SRB) (step S138).

This enables an efficient measurement without the frequencies of themeasuring objects overlapping.

Note that in the process described above, the SN may configure a portionof the measuring object in step S134. In this case, the measurementobject identifier may use the value reserved in advance for the SN. Thiscan increase the flexibility of the measurement configuration by the SN.

Next, an example of the measurement configuration in a case that themeasurement objects of the MN and the SN are independent from each otherwill be described using FIG. 15 and FIG. 16.

In FIG. 15, the MN configures a measurement configuration including ameasurement object independent from the SN to the terminal apparatus 2via an MCG SRB (step S152). Prior to this, the MN and the SN may notifyeach other of information on the measurement objects configured (stepS151).

The SN configures a measurement configuration including a measurementobject independent from the MN to the terminal apparatus 2 via an SCGSRB (step S153).

Here, an example of the measurement configuration configured in stepS152 and step S153 is illustrated in FIG. 16.

In FIG. 16, on the MN side, three measurement objects are configured forthe terminal apparatus 2, and two report configurations EUTRA(reportConfigEUTRAs) and one reportConfigInterRAT are configured.Combinations of these three reporting configurations and the measurementobjects respectively associated are configured with the measurementidentifiers. On the SN side, three measurement objects independent fromthe MN are configured for the terminal apparatus 2, and threereportConfigNRs are configured. Combinations of these three reportingconfigurations and the measurement objects respectively associated areconfigured with the measurement identifiers.

At this time, as for the serving cell, the serving cell in themeasurement on the MN side may be only the cell of the MN (MCG cell),and the serving cell in the measurement on the SN side may be only thecell of the SN (SCG cell).

In a case that the terminal apparatus 2 configured with the abovemeasurement configuration satisfies the condition of the reportingconfiguration configured by the MN (or, configured via the MCG SRB)(step S154), the terminal apparatus 2 notifies the MN of the measurementresult (via the MCG SRB) (step S155), or in a case that the terminalapparatus 2 satisfies the condition of the reporting configurationconfigured by the SN (or, configured via the SCG SRB) (step S156), theterminal apparatus 2 notifies the SN of the measurement result (via theSCG SRB) (step S157).

This allows the MN and SN to perform efficient measurements withoutbeing affected by the configuration of each other.

In the description of FIG. 16, the frequency of the measurement objectconfigured in the measurement on the SN side may be only the frequencyof the SCG serving cell, and the other frequencies may be configuredonly in the measurement on the MN side. For example, the SN may notifythe MN of information on the measurement object having the frequencywhich is other than the frequency of the SCG serving cell and isrequired to be measured (e.g., some or all of the information includedin the measurement object NR), and the MN may configure the measurementobject. By providing such constraints, it is possible to eliminate thepossibility that a combination of frequencies for the measurementsindependently configured by the MN and the SN respectively cannot beaccommodated in the radio configuration of the terminal apparatus 2.

Next, the measurement report will be described. FIG. 17 is a diagramillustrating an example of the measurement results (measResults)reported by the terminal apparatus 2 to the MN and/or the SN. Themeasurement results include some or all of a measurement identifier(measId) triggering the reporting, information (measResultPCell)including a received power (RSRP or SSRP) and/or reception quality (RSRQor SSRQ) of the PCell, measurement results of the neighbor cells(measResultNeighCells) corresponding to the measurement identifier, anda list of serving frequency measurement results(measResultServFreqList). The measurement results of the neighbor cellsmay include one or more measurement results for each RAT(measResultListEUTRA, measResultListNR, MeasResultListNR,measResultListUTRA, measResultListGERAN, and measResultsCDMA2000).

An example of the list of the serving frequency measurement results(measResultServFreqList) is illustrated in FIG. 18. As illustrated inFIG. 18, the list of the serving frequency measurement results mayinclude one or more serving frequency measurement results(MeasResultServFreq). The serving frequency measurement results mayinclude ServCellIndex as an identifier of the serving frequency,information (measResultPCell) including a received power (RSRP or SSRP)and/or a reception quality (RSRQ or SSRQ) of the SCell at thatfrequency, and a cell identifier of a cell in the neighbor cells at thatfrequency having the best reception power (RSRP or SSRP) and/orreception quality (RSRQ or SSRQ) and the received power (RSRP or SSRP)and/or the reception quality (RSRQ or SSRQ).

An example of the list of the measurement results of the neighbor cells(measResultListEUTRA, measResultListNR) is illustrated in FIG. 19. Asillustrated in FIG. 19, the list of the measurement results of theneighbor cells may include measurement results of one or more neighborcells (measResultEUTRA, measResultNR). The measurement result of theneighbor cell may include some or all of an identifier of a neighborcell (a physical cell identifier and a cell global identifier), andinformation (measResult) including a received power (RSRP or SSRP)and/or a reception quality (RSRQ or SSRQ) of the cell.

The list of the serving frequency measurement results(measResultServFreqList) of the above measurement results may be dividedinto the those of the cell of the MN and the cell of the SN (MCG andSCG). For example, the list of the serving frequency measurement resultsmay be divided into a list of MN cell serving frequency measurementresults (measResultServFreqListMCG) and a list of SN cell servingfrequency measurement results (measResultServFreqListSCG). Additionally,the measResultServFreqListMCG and the measResultServFreqListSCG may bereported to the MN and only measResultServFreqListSCG may be notified tothe SN.

In a case that a list of the measurement results for the neighbor cellsof the above measurement results is generated, only any group of the MCGand the SCG may be considered as a serving cell, and the cells of theremaining group may be considered as the neighbor cells. For example, ina case that the MCG is constituted cells of EUTRA and the SCG isconstituted cells of NR, the measurement report to the MN may bereported to the MN while considering only the MCG cells as the servingcells and the SCG cells as the neighbor cells and using measResultListNRif needed. The measurement report to the SN may be reported to the SNwhile considering only the SCG cells as the serving cells and the MCGcells as the neighbor cells and using measResultListEUTRA if needed.

In a case that the reporting described above is performed, the terminalapparatus 2 may determine, based on the information notified from theMN, the measurement results of any of the serving cells are included inthe measurement report reported to the MN and/or the SN. For example, ina case that information limiting the reporting for the SN is notified bythe MN, the terminal apparatus 2 may report the measurement resultsincluding those of the MCG cells and SCG cells as the measurementresults of the serving cell to the MN, and report the measurementresults including those of the SCG cells only as the measurement resultsof the serving cell to the SN. In a case that information limiting theoverall reporting is notified by the MN, the terminal apparatus 2 mayreport the measurement results including those of the MCG cells only asthe measurement results of the serving cell to the MN, and report themeasurement results including those of the SCG cells only as themeasurement results of the serving cell to the SN.

This allows the base station apparatus 3 to configure appropriate radioresources for the terminal apparatus 2.

A configuration of the apparatus in the embodiment of the presentinvention will be described.

FIG. 2 is a schematic block diagram illustrating a configuration of theterminal apparatus 2 according to the present embodiment. As illustratedin the drawing, the terminal apparatus 2 is configured to include aradio transmission and/or reception unit 20 and a higher layerprocessing unit 24. The radio transmission and/or reception unit 20 isconfigured to include an antenna unit 21, a Radio Frequency (RF) unit22, and a baseband unit 23. The higher layer processing unit 24 isconfigured to include a medium access control layer processing unit 25and a radio resource control layer processing unit 26. The radiotransmission and/or reception unit 20 is also referred to as atransmitter, a receiver or a physical layer processing unit. Acontroller controlling operations of the units, based on variousconditions may be separately provided.

The higher layer processing unit 24 outputs uplink data (transportblock) generated by a user operation or the like, to the radiotransmission and/or reception unit 20. The higher layer processing unit24 performs processing for some or all of the Medium Access Control(MAC) layer, the Packet Data Convergence Protocol (PDCP) layer, theRadio Link Control (RLC) layer, and the Radio Resource Control (RRC)layer.

The medium access control layer processing unit 25 included in thehigher layer processing unit 24 performs processing of the Medium AccessControl layer. The medium access control layer processing unit 25controls transmission of a scheduling request, based on various types ofconfiguration information/parameters managed by the radio resourcecontrol layer processing unit 26.

The radio resource control layer processing unit 26 included in thehigher layer processing unit 24 performs processing of the RadioResource Control layer. The radio resource control layer processing unit26 manages various types of configuration information/parameters of itsown apparatus. The radio resource control layer processing unit 26 setsvarious types of configuration information/parameters, based on higherlayer signaling received from the base station apparatus 3. Namely, theradio resource control layer processing unit 26 sets the variousconfiguration information/parameters in accordance with the informationindicating the various configuration information/parameters receivedfrom the base station apparatus 3.

The radio transmission and/or reception unit 20 performs processing ofthe physical layer, such as modulation, demodulation, coding, decoding,and the like. The radio transmission and/or reception unit 20demultiplexes, demodulates, and decodes a signal received from the basestation apparatus 3, and outputs the information resulting from thedecoding to the higher layer processing unit 24. The radio transmissionand/or reception unit 20 generates a transmit signal by modulating andcoding data, and transmits the generated signal to the base stationapparatus 3.

The RF unit 22 converts (down converts) a signal received via theantenna unit 21 into a baseband signal by orthogonal demodulation, andremoves unnecessary frequency components. The RF unit 22 outputs theprocessed analog signal to the baseband unit.

The baseband unit 23 converts the analog signal input from the RF unit22 into a digital signal. The baseband unit 23 removes a portioncorresponding to a Cyclic Prefix (CP) from the digital signal resultingfrom the conversion, performs Fast Fourier Transform (FFT) of the signalfrom which the CP has been removed, and extracts a signal in thefrequency domain.

The baseband unit 23 generates an SC-FDMA symbol by performing InverseFast Fourier Transform (IFFT) of the data, adds the CP to the generatedSC-FDMA symbol, generates a baseband digital signal, and converts thebaseband digital signal into an analog signal. The baseband unit 23outputs the analog signal resulting from the conversion, to the RF unit22.

The RF unit 22 removes unnecessary frequency components from the analogsignal input from the baseband unit 23 using a low-pass filter,up-converts the analog signal into a signal of a carrier frequency, andtransmits the up-converted signal via the antenna unit 21. Furthermore,the RF unit 22 amplifies power. The RF unit 22 may have a function tocontrol transmit power. The RF unit 22 is also referred to as a transmitpower controller.

Note that the terminal apparatus 2 may include pluralities of some unitsor pluralities of all the units in order to support transmission and/orreception processing in the same subframe of multiple frequencies(frequency bands or frequency band widths) or multiple cells.

FIG. 3 is a schematic block diagram illustrating a configuration of thebase station apparatus 3 according to the present embodiment. Asillustrated in the drawing, the base station apparatus 3 is configuredto include a radio transmission and/or reception unit 30 and a higherlayer processing unit 34. The radio transmission and/or reception unit30 is configured to include an antenna unit 31, an RF unit 32, and abaseband unit 33. The higher layer processing unit 34 is configured toinclude a medium access control layer processing unit 35 and a radioresource control layer processing unit 36. The radio transmission and/orreception unit 30 is also referred to as a transmitter, a receiver or aphysical layer processing unit. A controller controlling operations ofthe units, based on various conditions may be separately provided.

The higher layer processing unit 34 performs processing for some or allof the Medium Access Control (MAC) layer, the Packet Data ConvergenceProtocol (PDCP) layer, the Radio Link Control (RLC) layer, and the RadioResource Control (RRC) layer.

The medium access control layer processing unit 35 included in thehigher layer processing unit 34 performs processing of the Medium AccessControl layer. The medium access control layer processing unit 35performs processing associated with a scheduling request, based onvarious types of configuration information/parameters managed by theradio resource control layer processing unit 36.

The radio resource control layer processing unit 36 included in thehigher layer processing unit 34 performs processing of the RadioResource Control layer. The radio resource control layer processing unit36 generates, or acquires from a higher node, downlink data (transportblock) allocated on a physical downlink shared channel, systeminformation, an RRC message, a MAC Control Element (CE), and the like,and outputs the generated or acquired data to the radio transmissionand/or reception unit 30. The radio resource control layer processingunit 36 manages various types of configuration information/parametersfor each of the terminal apparatuses 2. The radio resource control layerprocessing unit 36 may set various types of configurationinformation/parameters for each of the terminal apparatuses 2 via thehigher layer signal. Namely, the radio resource control layer processingunit 36 transmits/broadcasts information indicating various types ofconfiguration information/parameters.

The functions of the radio transmission and/or reception unit 30 issimilar to the functionality of the radio transmission and/or receptionunit 20, and hence description thereof is omitted. Note that in a casethat the base station apparatus 3 is connected to one or moretransmission reception points 4, some or all of the functions of theradio transmission and/or reception unit 30 may be included in each ofthe transmission reception points 4.

The higher layer processing unit 34 transmits (transfers) or receivescontrol messages or user data between the base station apparatuses 3, orbetween a higher network apparatus (MME or Serving-GW (S-GW)) and thebase station apparatus 3. Although, in FIG. 3, other constituentelements of the base station apparatus 3, a transmission path of data(control information) between the constituent elements, and the like areomitted, it is apparent that the base station apparatus 3 is providedwith multiple blocks, as constituent elements, including other functionsnecessary to operate as the base station apparatus 3. For example, aRadio Resource Management layer processing unit or an application layerprocessing unit exists in the higher level than the radio resourcecontrol layer processing unit 36.

Note that “units” in the drawing refer to constituent elements torealize the functions and the procedures of the terminal apparatus 2 andthe base station apparatus 3, which are also represented by the termssuch as a section, a circuit, a constituting apparatus, a device, aunit, and the like.

Each of the units designated by the reference signs 20 to 26 included inthe terminal apparatus 2 may be configured as a circuit. Each of theunits designated by the reference signs 30 to 36 included in the basestation apparatus 3 may be configured as a circuit.

Various aspects of the terminal apparatus 2 and the base stationapparatus 3 according to the embodiment of the present invention will bedescribed.

(1) A first aspect of the present invention is a terminal apparatus forreceiving a measurement configuration from one or more base stationapparatuses, the measurement configuration including a measurementobject, a reporting configuration, and a measurement identifier, themeasurement object including at least an identifier for individuallyidentifying the measurement object (measurement object identifier) andinformation of a frequency to be measured, the reporting configurationincluding at least an identifier for individually identifying thereporting configuration (reporting configuration identifier) andinformation of a condition to be reported, and the measurementidentifier being an identifier for individually identifying informationfor indicating a combination of the measurement object identifier andthe reporting configuration identifier, the terminal apparatus includinga receiver configured to receive the measurement configuration and thereporting configuration via a first signaling radio bearer (first SRB),and receive the reporting configuration via a second signaling radiobearer (second SRB), a controller configured to select a measurementobject indicated by the measurement identifier received via the firstSRB from the measurement configuration received via the first SRB andselect a reporting configuration indicated by the measurement identifierfrom the measurement configuration received via the first SRB, andfurther select a measurement object indicated by the measurementidentifier received via the second SRB from the measurementconfiguration received via the first SRB and select a reportingconfiguration indicated by the measurement identifier from themeasurement configuration received via the second SRB, and a transmitterconfigured to transmit via the first SRB a measurement resultcorresponding to the measurement identifier received via the first SRB,and transmit via the second SRB a measurement result corresponding tothe measurement identifier received via the second SRB.

(2) A second aspect of the present invention is a base station apparatusfor transmitting a measurement configuration to a terminal apparatus,the measurement configuration including a measurement object, areporting configuration, and a measurement identifier, the measurementobject including at least an identifier for individually identifying themeasurement object (measurement object identifier) and information of afrequency to be measured, the reporting configuration including at leastan identifier for individually identifying the reporting configuration(reporting configuration identifier) and information of a condition tobe reported, and the measurement identifier being an identifier forindividually identifying information for indicating a combination of themeasurement object identifier and the reporting configurationidentifier, the base station apparatus including a transmitterconfigured to use information on a measurement object notified fromanother base station apparatus (a second base station apparatus) toselect a measurement object identifier indicated by a measurementidentifier to be notified to the terminal apparatus and transmit themeasurement identifier and the reporting configuration to the terminalapparatus.

(3) A third aspect of the present invention is a communication methodapplied to a terminal apparatus for receiving a measurementconfiguration from one or more base station apparatuses, the measurementconfiguration including a measurement object, a reporting configuration,and a measurement identifier, the measurement object including at leastan identifier for individually identifying an individual measurementobject (measurement object identifier) and information of a frequency tobe measured, the reporting configuration including at least anidentifier for individually identifying the reporting configuration(reporting configuration identifier) and information of a condition tobe reported, and the measurement identifier being an identifier forindividually identifying information for indicating a combination of themeasurement object identifier and the reporting configurationidentifier, the communication method including the steps of receivingthe measurement configuration and the reporting configuration via afirst signaling radio bearer (first SRB) and receiving the reportingconfiguration via a second signaling radio bearer (second SRB),selecting a measurement object indicated by the measurement identifierreceived via the first SRB from the measurement configuration receivedvia the first SRB and selecting a reporting configuration indicated bythe measurement identifier from the measurement configuration receivedvia the first SRB, and further selecting a measurement object indicatedby the measurement identifier received via the second SRB from themeasurement configuration received via the first SRB and selecting areporting configuration indicated by the measurement identifier from themeasurement configuration received via the second SRB, and transmittingvia the first SRB a measurement result corresponding to the measurementidentifier received via the first SRB and transmitting via the secondSRB a measurement result corresponding to the measurement identifierreceived via the second SRB.

(4) A fourth aspect of the present invention is a communication methodapplied to a base station apparatus for transmitting a measurementconfiguration to a terminal apparatus, the measurement configurationincluding a measurement object, a reporting configuration, and ameasurement identifier, the measurement object including at least anidentifier for individually identifying the measurement object(measurement object identifier) and information of a frequency to bemeasured, the reporting configuration including at least an identifierfor individually identifying the reporting configuration (reportingconfiguration identifier) and information of a condition to be reported,and the measurement identifier being an identifier for individuallyidentifying information for indicating a combination of the measurementobject identifier and the reporting configuration identifier, thecommunication method including a step of using information on ameasurement object notified from another base station apparatus (asecond base station apparatus) to select a measurement object identifierindicated by a measurement identifier to be notified to the terminalapparatus and transmit the measurement identifier and the reportingconfiguration to the terminal apparatus.

(5) A fifth aspect of the present invention is an integrated circuitmounted on a terminal apparatus for receiving a measurementconfiguration from one or more base station apparatuses, the measurementconfiguration including a measurement object, a reporting configuration,and a measurement identifier, the measurement object including at leastan identifier for individually identifying the measurement object(measurement object identifier) and information of a frequency to bemeasured, the reporting configuration including at least an identifierfor individually identifying the reporting configuration (reportingconfiguration identifier) and information of a condition to be reported,and the measurement identifier being an identifier for individuallyidentifying information for indicating a combination of the measurementobject identifier and the reporting configuration identifier, theintegrated circuit causing the terminal to exert receiving themeasurement configuration and the reporting configuration via a firstsignaling radio bearer (first SRB) and receiving the reportingconfiguration via a second signaling radio bearer (second SRB),selecting a measurement object indicated by the measurement identifierreceived via the first SRB from the measurement configuration receivedvia the first SRB and selecting a reporting configuration indicated bythe measurement identifier from the measurement configuration receivedvia the first SRB, and further selecting a measurement object indicatedby the measurement identifier received via the second SRB from themeasurement configuration received via the first SRB and select areporting configuration indicated by the measurement identifier from themeasurement configuration received via the second SRB, and transmittingvia the first SRB a measurement result corresponding to the measurementidentifier received via the first SRB and transmitting via the secondSRB a measurement result corresponding to the measurement identifierreceived via the second SRB.

(6) A sixth aspect of the present invention is an integrated circuitmounted on a base station apparatus for transmitting a measurementconfiguration to a terminal apparatus, the measurement configurationincluding a measurement object, a reporting configuration, and ameasurement identifier, the measurement object including at least anidentifier for individually identifying the measurement object(measurement object identifier) and information of a frequency to bemeasured, the reporting configuration including at least an identifierfor individually identifying the reporting configuration (reportingconfiguration identifier) and information of a condition to be reported,and the measurement identifier being an identifier for individuallyidentifying information for indicating a combination of the measurementobject identifier and the reporting configuration identifier, theintegrated circuit causing the terminal apparatus to exert usinginformation on a measurement object notified from another base stationapparatus (a second base station apparatus) to select a measurementobject identifier indicated by a measurement identifier to be notifiedto the terminal apparatus and transmit the measurement identifier andthe reporting configuration to the terminal apparatus.

Consequently, the terminal apparatus 2 and the base station apparatus 3can communicate efficiently.

Note that the embodiments discussed thus far are merely examples, andthe embodiments can be implemented using various kinds of modifications,replacement, or the like. For example, an uplink transmission scheme canbe applied to both communication systems of a Frequency Division Duplex(FDD) scheme and a Time Division Duplex (TDD) scheme. The names of theparameters, events, and the like indicated in the embodiments are givenfor the sake of convenience of description; therefore, even in a casethat the actual applied names differ from the names in the embodimentsof the present invention, the spirit of the invention claimed in theembodiments of the present invention is not affected in any way.

The term “connection” used in the respective embodiments is not limitedto the configuration in which a certain apparatus and another apparatusare directly connected using a physical line, and includes aconfiguration in which the devices are logically connected, aconfiguration in which the devices are radio-connected using the radiotechnology, and the like.

The terminal apparatus 2 is also called a user terminal, a mobilestation apparatus, a communication terminal, a mobile apparatus, aterminal, User Equipment (UE), and a Mobile Station (MS). The basestation apparatus 3 is also called a radio base station apparatus, abase station, a radio base station, a fixed station, a NodeB (NB), anevolved NodeB (eNB), a Base Transceiver Station (BTS), a Base Station(BS), an NR NodeB (NR NB), an NNB, a Transmission and Reception Point(TRP), and a next generation Node B (gNB).

The base station apparatus 3 according to one aspect of the presentinvention can also be realized as an aggregation (an apparatus group)including multiple apparatuses. Each of the apparatuses configuring suchan apparatus group may include some or all portions of each function oreach functional block of the base station apparatus 3 according to theabove-described embodiment. The apparatus group may include each generalfunction or each functional block of the base station apparatus 3.Furthermore, the terminal apparatus 2 according to the above-describedembodiment can also communicate with the base station apparatus 3 as theaggregation.

Furthermore, the base station apparatus 3 according to theabove-described embodiment may serve as an Evolved Universal TerrestrialRadio Access Network (EUTRAN) or a Next Generation Core network (NextGenCore). The base station apparatus 3 according to the above-describedembodiment may have some or all of the functions of a node higher thanan eNodeB.

A program running on an apparatus according to an aspect of the presentinvention may serve as a program that controls a Central Processing Unit(CPU) and the like to cause a computer to operate in such a manner as torealize the functions of the above-described embodiment according to thepresent invention. Programs or the information handled by the programsare temporarily read into a volatile memory, such as a Random AccessMemory (RAM) while being processed, or stored in a non-volatile memory,such as a flash memory, or a Hard Disk Drive (HDD), and then read by theCPU to be modified or rewritten, as necessary.

Note that the apparatuses in the above-described embodiment may bepartially enabled by a computer. In that case, this configuration may berealized by recording a program for realizing such control functions ona computer-readable recording medium and causing a computer system toread the program recorded on the recording medium for execution. Notethat the “computer system” herein refers to a computer system built intothe apparatuses, and the computer system includes an operating systemand hardware components such as a peripheral device. Furthermore, the“computer-readable recording medium” may be any of a semiconductorrecording medium, an optical recording medium, a magnetic recordingmedium, and the like.

Moreover, the “computer-readable recording medium” may include a mediumthat dynamically retains the program for a short period of time, such asa communication line that is used to transmit the program over a networksuch as the Internet or over a communication line such as a telephoneline, and a medium that retains, in that case, the program for a certainperiod of time, such as a volatile memory within the computer systemwhich functions as a server or a client. Furthermore, theabove-described program may be configured to realize some of thefunctions described above, and additionally may be configured to realizethe functions described above, in combination with a program alreadyrecorded in the computer system.

Furthermore, each functional block or various characteristics of theapparatuses used in the above-described embodiment may be implemented orperformed on an electric circuit, that is, typically an integratedcircuit or multiple integrated circuits. An electric circuit designed toperform the functions described in the present specification may includea general-purpose processor, a Digital Signal Processor (DSP), anApplication Specific Integrated Circuit (ASIC), a Field ProgrammableGate Array (FPGA), or other programmable logic devices, discrete gatesor transistor logic, discrete hardware components, or a combinationthereof. The general-purpose processor may be a microprocessor, orinstead, a known type of a processor, a controller, a micro-controller,or a state machine. The general-purpose processor or the above-mentionedcircuits may be configured of a digital circuit, or may be configured ofan analog circuit. Furthermore, in a case that with advances insemiconductor technology, a circuit integration technology appears thatreplaces the present integrated circuits, it is also possible to use anintegrated circuit based on the technology.

Note that the invention of the present patent application is not limitedto the above-described embodiments. In the embodiment, apparatuses havebeen described as an example, but the invention of the presentapplication is not limited to these apparatuses, and is applicable to aterminal apparatus or a communication apparatus of a fixed-type or astationary-type electronic apparatus installed indoors or outdoors, forexample, an AV apparatus, a kitchen apparatus, a cleaning or washingmachine, an air-conditioning apparatus, office equipment, a vendingmachine, and other household apparatuses.

The embodiments of the present invention have been described in detailabove referring to the drawings, but the specific configuration is notlimited to the embodiments and includes, for example, an amendment to adesign that falls within the scope that does not depart from the gist ofthe present invention. Furthermore, various modifications are possiblewithin the scope of one aspect of the present invention defined byclaims, and embodiments that are made by suitably combining technicalmeasures disclosed according to the different embodiments are alsoincluded in the technical scope of the present invention. Furthermore, aconfiguration in which constituent elements, described in the respectiveembodiments and having mutually the same effects, are substituted forone another is also included in the technical scope of the presentinvention.

INDUSTRIAL APPLICABILITY

An aspect of the present invention can be utilized, for example, in acommunication system, communication equipment (for example, a cellularphone apparatus, a base station apparatus, a radio LAN apparatus, or asensor device), an integrated circuit (for example, a communicationchip), or a program.

REFERENCE SIGNS LIST

-   2 Terminal apparatus-   3 Base station apparatus-   20, 30 Radio transmission and/or reception unit-   21, 31 Antenna unit-   22, 32 RF unit-   23, 33 Baseband unit-   24, 34 Higher layer processing unit-   25, 35 Medium access control layer processing unit-   26, 36 Radio resource control layer processing unit-   4 Transmission reception point

1-3. (canceled)
 4. A terminal apparatus comprising: reception circuitryconfigured to receive a first measurement configuration and a secondmeasurement configuration; and control circuitry configured to perform ameasurement based on the first measurement configuration or the secondmeasurement configuration, wherein one or more cells of a master cellgroup and one or more cells of a secondary cell group are configured asserving cells of a dual connectivity, the first measurementconfiguration of a measurement event to compare a measurement result ofa serving cell of the master cell group with a first threshold isconfigured by an EUTRA RRC message, the second measurement configurationof a measurement event to compare a measurement result of a serving cellof the secondary cell group with a second threshold is configured by anNR RRC message, and the first measurement configuration of a measurementevent to compare a measurement result of a serving cell of the mastercell group with a third threshold and compare a measurement result of anNR neighbour cell with a forth threshold is configured by an EUTRA RRCmessage.
 5. The terminal apparatus according to claim 4, wherein theserving cell of the secondary cell group is considered as the NRneighbour cell in a case that the measurement result of the NR neighbourcell is compared with the forth threshold.
 6. A communication method fora terminal apparatus, the communication method comprising: receiving afirst measurement configuration and a second measurement configuration;and performing a measurement based on the first measurementconfiguration or the second measurement configuration, wherein one ormore cells of a master cell group and one or more cells of a secondarycell group are configured as serving cells of a dual connectivity, thefirst measurement configuration of a measurement event to compare ameasurement result of a serving cell of the master cell group with afirst threshold is configured by an EUTRA RRC message, the secondmeasurement configuration of a measurement event to compare ameasurement result of a serving cell of the secondary cell group with asecond threshold is configured by an NR RRC message, and the firstmeasurement configuration of a measurement event to compare ameasurement result of a serving cell of the master cell group with athird threshold and compare a measurement result of an NR neighbour cellwith a forth threshold is configured by an EUTRA RRC message.
 7. Thecommunication method according to claim 6, wherein the serving cell ofthe secondary cell group is considered as the NR neighbour cell in acase that the measurement result of the NR neighbour cell is comparedwith the forth threshold.